:::::r

,~

!l:

-,

UNIVERSITY OF ILLINOIS

Experiment Station.\

AgriculturalURBANA, JULY, 1898.

BULLI;TIN NO. ,3.!

~

~-

THE CHEMISTRY.' Or THE CORN KERNELJ.INTRODUCTION.-The object of these sfudies on the chemisty of corn2

is to trace its historical development, to bring together from manysources the existing knowledge of the subject, and, if possible, to addthereto in certain lines where our present knowledge seems most defi-ci~nt, omitting fields wherein other investigators are known to beengaged. With the single purpose of being faithful to the history of

the subject, I have felt equally free to point out misconceptions, erron-eous concI&sions, or real advances of past investigations. The subjecthas natural~y divided itself into two parts:

1St. the proximate compo$ition of corn, which has a very prac-tical signifibance as indicating its value as food for man and domesticanimals and as raw material for various manufacturing purposes.

2nd. '[he complete and exact composition of the different groupsof substances found by proximate analysis, a matter of more purelyscientific irlterest, though not without phases of economic importance.

ACKNOWLEDGMENTs.-I ackI?-°wledge with pleasure and gratitudemy indebtedness to the Department of Chemistry of Cornell University for

the opportu~ities and privileges wpich have been freely accorded to me.I am especitIly grateful to Profess,or G. C. Caldwell, under whose direc-tion these s~udies have been carri~d on, and who has been to me a con-stant source of counsel and encodragement.

--~-1 Presented to the Faculty of Cornell University as a thesis for the degree of

Doctor of Philosophy, June, 1898. -2Indian corn. maize; Ger. 117(iZschkorn, lI£ais; Fr. mat's: Sp. mai2: from Hay-

tian maids. (Zea Mays L.)

f3° [july,BULLETIN NO, 53,

I am also indebted to the University of Illinois Agricultural Experi-ment Station for the privilege of selecting samples from corn which hadbeen carefully grown under known conditions upon the Station plots,and for some experimental data,

PART I.-THE PROXIMATE COMPOSITION OF CORN,

HISTORICAL.

The earliest record known to the writer of work on the proximatecomposition of corn was pubEshed' in 1821; and, because of the interestand importance which attach to it, the article is here quoted in full:

"ANALYSIS OF INDIAN CORN,-Indian corn, either alone or mixed with the flour

of wheat or of rye, constitutes a considerable article in the food of the inhabitants of

the United States. In consequence of the importance which thus belonged to it, Dr,

John Gorham of Harvard University, Cambridge. U. S" was induced to examine itchemically, with great attention, His experiments were made upon two varieties of

maize, that producing small, yellow grain, and the large, flat and white kind, com-

monly known by the name of Virginia corn: but the results were so similar, that only

those belonging to the former kind have been given, One hundred grains [weight]powdered, when macerated and triturated with great precaution in water, gave a clear

filtered solution, which, on evaporation, afforded four grains of greyish semi-trans-

parent substance, disposed in lamin~. Of this, when acted upon by alcohol, I 75

grains were insoluble, and resembled gum; the 2.25 grains that were soluble, were

separated from the alcohol by evaporation, and dissolved in water, then being acted

on by acetate of lead and sulphuretted hydrogen, ,8 of a grain of extractive matter

was obtained, and 1.45 grains of a saccharine matter remained,Another portion of the mixed gummy and saccharine matter was obtained; a

drop of sulphuric acid was added to a part of it, and liberated acetic acid, and quick-

lime being added to another part, a small quantity of ammonia was liberated. Hence

it appears to contain acetate of ammonia. It also afforded a portion of phosphate of

lime

The portion unacted on by water, and left on the filter, was digested for twenty-

four hours in alcohol, and the clear solution evaporated; a yellow substance was then

obtained, resembling bees'-wax in appearance. It was 50ft, ductile, tenacious, elastic,

insipid, nearly inodorous, and heavier than water, When heated, it swelled, became

brown, exhaled the odor of burning bread, melted with the smell of animal matter,

and left a voluminous charcoal. It burnt in the flame of a lamp, but not rapidly,

When distilled, no ammonia seemed formed, It was insoluble in water, but soluble

in alcohol, oil of turpentine, and sulphuric ether, and sparingly in mineral acids andcaustic alkalies. It was insoluble in fixed oils, but mixed with resin, The quantity

obtained from roo grains was three grains,

This substance appears to differ from all known'vegetable bodies, and 'has been

called zeine by Dr. Gorham, It resembles gluten in some circumstances, but differs

from it in containing no azote, in its great solubility in alcohol, and in its perma-nency, not undergoing any obvious change in six weeks, On the other hand, it is

analogous to the resins in its solubility in alcohol, essential oils, alkalies, and partial

solubilities in acids It is inflammable, and probably composed of oxygen, hydrogen,

and carbon. It may easily be obtained by digesting a few ounces of the meal from

1 (London; Quarterly Tournai of Science, Literature, and the Arts (I82I) II,

This Journal was published from I8I7 to I828 only.206

I1898, ] i CHE. MISTRY

i(H" THE CORN

KERNEL.J; '3'the y,ello

i corn in a flask with warn! alcohol allowi'

filtermg apd evaporating,i '

ng It to rest for some hours, then

Aftet the action of alcohol on tbe I"of w t I

00 grains, It was boiled' ,a er, a arge quantity of starch wa

th d"

In sUccessIve portionsst h'

. s us Issolved leav' ,ance, w 1ch, when boiled with weak I

h' "

Ing I4.25 grams of a sub.The acid solution, when concentrated d:;:S'tU~C aCId, was reduced to

3.75 grainsalbumen, and it appeared that about ~ ,I

ef 2.25 grains of what was considered

acid, The 3.75 grains of solid mattgraInS 0 starch had also been taken up by the

,

fer were then heated with

3 graIns a ligneous matter andt ' I

'

, potassa, and reduced to,

d'

cu IC e containIng a littlh hportIOn Issolved appeared to b I

b,e p osp ate of lime; the

fe a umen AccordIn g t th'uents 0 yellow Indian corn in th 0 IS analysis the constit-, e common and the dry state, will be as follows.

Water, , , , , , , , , Common state, Drystate.

Starch. .. .. .. .. :'" :

'

,.. , , , , , ,

.. , , ,'.. 9,00

Zein~ """"'!""""'" "'...,77.00

~~bul:;~~~;t~~:: ': ': ':::

,''',',',',',:,''', '"',",',',,'" ',,',',', ~',~~

sacdarine matter'

, , ,

""""""""""

1,75

Extr~ctic matter' '"

,

"

, , , ,. , , , , , , , , , , , , ,

"

1, 45Cutic;le and ligne~~~'fi'br'e"""""

""""" ".80

Phosl Carbo SuI. of lime, ;~d i~s's',', ',,' ','. , , , , , , ,

3,00

1,50

134,599

3.296

2,747

1,922

1,593,

879

3,296

J,648

T I roo, 99,9130, he P?wder of the corn is hygrometric

and'

wIth the state of the atmos p here S'

,'.

the quantIty of water in it varies

h'

, . omehmes It would Iot er hmes bot more than half tha

t U',ose 12 per cent. on drying at

II, q, antIty.

', n SOlne expenments on the colo~in matter of'Indian corn!, it was found to be solu'l g,

bthe dIfferent colored varieties of

g b Ikl, P e In oth water and I

h Ireen y a fihes, and red by acids, I a co 0, and to become

, A spir~tous liquor may be obtaihed from Indianchan ges whIch tak I

'

Corn, in con sequence of thee p ace In its saccharinematter."

Although the analysis does not a roacmineral matter it

Possess f

pp h exactness except as to the, es some eatures ofPe ]'

,which may be mentioned th d

"

cu lar Interest, amonge ate at whIch It was

I jCovery and isolation of thet ' d b '

mac e, ant the dis-pro el ad y pecu liar to tJ

namely, zeitt, obtained by extractin'tl

1e corn kernel,

dered corn insoluble in wt d

g WI 1 a~cohol the residue of pow-

a er, an eva poratm g th I h'dryness,

'e a co olIc ex tract to

In 182,3 the Italian chemist Bizio , re p ort ed l the followino- anah'sis'Salts, acids, etc."

~.

~;:~~""""""",..,',',,',',',',',',' ~",' ','.',', ,',',',',', ,'.' ',',',',','.',','~,':::: ::: 5 :;~

Sugar,;, , , ,

"

, , . ,',',',',',',',',','

, ,. , , , , , , , , , , , ,

. . , , ,

"

, ,. .95

GumI

"" """"""'""""."""",Hord 'el

:b"

" " "

" " '

, , , , , , , , , , , , ,.

, , , , , , ,

,>..

2

9

9

0. . .

"'.". . . . .

'". .. ... ..

-Extractive ma't;~;

, , , , , , , , ,

" """"""""""".,.""",7, 7 1

~t~~~hr::::"" ,''',',',',',',',',''''''',',''',:::::::::::':::::::::::,:::: I

:~;

'Tournall [SCh~~i'g'g'e'r~'~i;; ~~~~'ii~~~' ;~;~i~' ;~~~~)' ~~"""'".80,C)J

I I

'377,

r"

132BULLETIN NO. 53,

[Jury,

. .1 h ' h h d ot been discoveredB" fund corn to contam OJ, W IC a nIZIO 0

'11 d by Bizio because'b 'Gorham. The substance, hordezn, was so ca e ,

0:- its similarity to the substance which had been obtamed f;tOm

Proustl and so named by himj which, however, was a er-bar1~yhb:wn b Guibourt2 to be merely a mixture of hulls and, cellular

~ar s Yhordein as found by Bizio was doubtless a mixture of

~~:~ee; fi~~:u:h:ubstances with considerable amounts of adhering starch

and~ot~~:IY the first work from the record of which the total amount.

roatte r can be very approximately calculated was thatof nitrogenous m . t t of

.. I blished3 in 1836 upon the total nitrogen con enof Bousmgau t, pu" 'd 6 7 grammes of corn (con-

~o,r~, BY8

cO

e

mr

bcU

e

S

n

tl

t

ono;l:hat:~ )P~::e o~~u~d

1to yield 10,3 cubic centi-

tamm g 1 p' .' II '

B. d t degrees and 738 ml Imeters. Ymeters of nitrogen gas measure a 9 f i ro en in

t fon I find this to be equivalent to 2,39 per cent. 0 n tg

f~1~:X~y

a~atter, and by using the factor 6,25, this gives 14.9 per cent. 0

prote;:'186 Horsford report~d' a complete ultimate organ.ic analysis of ,

4.' s use of the formula which had been

corn and then by an mgenlOu .'com osition of several proteid bodies, as egg-

worked" out for the :veragef

hP t e etc he calculated tbe ultimatealbumen, gluten (Rieber) a w ea, ry, ., nitro-, . I of the nitrogenous matter, but also of the'compositIOn n~t on

~ Using the factor 6.375 for converting nitrogengen-free organic ma :r.d 'd the Percentage of mineral matter

into protein, and havmg etermme,.he gives corn the following compositIOn:

Nitrogenous matter. , ,

"

, , , , ., 14,66

Carbon, , , . , , , . . . . . . .Hydrogen, , , ., .",..

Ni trogen, , , .. .'

, , . . ,'

Sulfur., ..,.."."..Oxygen,

', . . , , , . , , . , ,

8,07

1.00

2,30

.16

3,13

Non-nitrogenous organic matter. 84.52

Carbon. . . . . ..'. , ,

"37-38

Hydrogen.. .. , ..'.. .. 5.61

Oxygen."""".,... 41.53

1.92

Mineral matter, , . . . .'

, , , . . , ,'

I ,92

- '-~~-~~ales de Chimie et de P~ysiqu,e ~817)' h[~~t 5'd;;7~hysischen Wissenschaften2Jahresbericht [Berzelius] uber dIe ortsc n e

(1831) 10, 2~2.d Chimie et de Physique (1836) [2] 63,

239'3 Anna es e . h made (18 6) 58, 182,'Annalen der Chemle und P ar

'b'd ( : ) 40 65' Heldt, ibid, (1843) 45, 198,6Scberer, ibid, (1841) 40, r; Jones, I I '

I 41 , ,

1898.] CHEMISTRY. OF THE CORN KERNEL.

~ II llU

133

A very extended article by J, H. Salisbury on the general subjectof corn was pubiishedl in 1848, It included a report of considerablechemical work, done by such imperfect methods as nearly to deprive itof permanent value, as wiII appear from the following analysis of twosamples of corn kernels:

1.

Albumen. . , . , , , , ,.' ""...,.,..,."".""""

9,29

Zein, , , , , , ,

"

, ,

". ,

"

, , ." """"""'."""

6,73

Cas~in ", """"" ". .,."..",."""." 1 ,44

Dex!trine or gum, , . . , , . , , .,"."..",' ,,'.' 5,94

Fib~r"""""''''''''''

,."..",.".."".,12, 09

Mat~er separated from fiber by weak potash solution, 7,80

sugfr and extract",.,.""""""""""""

13,27

~ti~r: ,',',:: :','.:',:'.:', :::',',',',",', ',',',:',',::: ',:::::' :3~',~~

2.

4,64

3,98,09

3,53,96

6.48

1'4,4260,92

4,98

The methods employed by Salisbury were in the main similar tothose of t'ihe earlier investigator:; and are brieRy indicated as follows:

The \powdered corn was tashed with water which was decanted.The residpe extracted with aloohol and dilute potash water gave thefiber. T~e matter held in susp~nsion in the water was collected, washedwith alcohol and noted as star~h, the resid ue from the evaporation ofthe alcohol became a portion o~ the "sugar and extract." The turbidwater from the starch determil\lation was heated and the coagulatedmatter called albumen, In one portion of the filtrate the "casein" wasprecipitated by acetic acid, and the "dextrine or gum" by alcoh 0] afterpartial evaporation, In a second portion the "casein" and "dextrineor gum" were together removed by alcohol and anotha portion of

"sugar and extract" obtained by evaporating the filtrate to dryness,The zein and oil were extracted from the corn by alcohol and

separated by ether after evaporation of the alcohol.

Follo"fing Salisbury's work proximate analyses were reported byPolson", Pqggiale3, Stepf" Payen~;, and also by the renowned and but re-cently deceased R. Fresenius". '

I-'

I I

'Trans~ctions of the New York State Agricultural Society (1848) 8,678; Ameri-can Journal df Science and Arts (1849) [2] 8, 307.

2Cbimi~. Gazette (1855) 2II; Journal fur praktische Chemie (1855) 66, 320,3Jahresbericht [Lei big und Kopp) uber die Fortschritte der Chemie (1856) 809"Journal fur praktiscbe Chemie (1859) 76,88,6Landwirtscbaftliche Versuchs.S~ationen' (1859) I, 179; Jahresberich t [Hoff.

mann] uber die Fortschritte auf dem G:.esammtgebiete der Agricultur-Cbemie (1859)2, 76,

\

.

\

\

T34 [.I/I~), ,BULLETIN NO. 53.

The following will serve as illustrations of the results:

Polson,Water , 11.8 dry

Ash. . . . . . . . . . . . .. I. 8 2.°4Protein.. .. . .. 8.9 10.°9Oil. . . . . . . . . . . . . .. 4. 4 4 .99Fiber.. .. 15.9 18.°3Sugar ... 2.9' 3.29Starch

""""".54.3 61.56

Poggiale.

13.5 dryI . 4 I . 62

9.9 rI . 446.7 7.754.02 4.62

Fresenius.

13.46 dryI . 58 I . 83

10 .°4

I 1. 60

5.Il 5.90

1.58 1.83

2.33" 2.6965.90 76. IS64.5 74.57

In 1369, Atwater reported' the following results from a study" of theproximate composition of corn :

Early Dutton.Ash. . . . . . . . . . . . . . . . . . . . .. 1.66Protein. . . . . . . . . . . . . . . . . . . . . . . .10.46Fat. . . . . . . . ..

""""""'"6.16

Fiber. . . . . . . . . . . . . . . . - . . . . . . .. 2.74Sugar. . . . - . . . . . . . . . . . . . . . . .. . 3.26Gum. . . . . . . . . . . . . . . . . . . . . . . . .. 4.59Starch. . .. . . . . . . .. . . .. 71.13

Common yellow,

1.4610.86

4.942.68

5.342.64

72.08

King Philip.

1. 7713.16

4.932.453.38

5.32

68.99

The protein was estimated by multiplying the total nitrogen by thefactor 0.25, a method which had come into general use, and which hasalready been referred to under Horsford's work. Sugar was estimatedby Fehling's method from the aqueous extract, and the gum is the

difference between the sugar and the dried aqueous extract. The oil isthe ether extract. Fiber was determined by extracting with dilute acidand alkali, essentially the method employed by Gorham nearly eightyyears ago, and in general use among agricultural chemists of to-day,having been known under various names, as Peligot's\ Henneberg's, orthe Weellde7 method, the last being common at the present time. Starchwas estimated by difference.

Closely following Atwater's work numerous analyses were reportedby European chemists. In the group of carbohydrates only the fiber

was determined, the remainder being estimated by difference and re-ported under the negati ve and indefinite heading "nitrogen-free extract"for which I have recently proposeds to substitute the more definite andlogical term cllrbollydrllte extract.

-" ~--~

'and gum-2and loss."dextrine,4W. O. Atwater-The proximate composition of several varieties of American

maize-Thesis for the degree of Doctor of Philosophy, Yale College (1869); Ameri-can Journal of Science and Arts (1869) [2] 48, 352.

"The analysis of a sample of ~weet corn also reported is omitted,6Journal fiir praktische Chemie (1850) 50, 261,1Landwirtschaftliche Versuchs-Stationen (1864) 6, 497-.University of Illinois Agr, Exp. Station Bulletin (1896) 43,

.e."" '..

.~:,Ji~)'\t

1898.J

I

. Th'I'e following table giJes a num berb 1 of the results obtained, a])emg ree uced to the basis

ofi dry matte!' :

i Analyst', Adh. Pt'Dietrich ,ro em- Fat. . . . . -

"""" -3 .,It} I 3 81-\ 5 O

(

Nessler. . . . . . i - . .)) 2.86 74.48N I

4.53 8.81 51-\7 I) 2ess er.

'. -. 4 74.55

Nessler""""''''''-..3.2~ 6.41 6.17 1).54 77.fjS

Kreuzh~~~""""'''...3.9 10.01 6.25 5.35 74.4'.."" ""''''

I . 70 13 034 7Honig und Brimmer.. .. .1.50

. ..'i [.74 78.74

Honig und Brimmer'9.00 4.10 1.5K

83.76

.1.42 10.35 4.36 1.55 82.32

.In 1883 RIchardson" made a com ilation .

III various parts of the Unitedp

.of analyses of corn grown

Th f II . States dunng the years 1877 to 188e 0 owmg table shows the ,number of s I -'.

'"

,2.

ages of th, e I f. i

,amp e:; analyzed and the aver-ana yses rom eachl state re p re t d \1/than asl{ t . .: . sen e. ! dry ma tter other

"

pro em, and od I have grouped u Iulrbollvdrater Th", d f '

-ne er the general term

. ':"IS IS one or several reasons.!.

vV>-' .mg not complete but. i . e are consldel-I proxImate analysIs. 2. Ash )rot' f. ,

carbohyc)rates constitute distin tl d'ff .' J eIn, at, and

dividual 'properties or charactC ~t' ~

erent groups wIth well known in-

. '

ens leS as to use, value, etc"

I' hamount O,f fiber In corn is too sn II t . . ,). e

naril yI

'f '

. 1a 0 warrant ItS determinationordi-, even I It were known that it 1 j'ff

other carbonydrates. th . s va ue e 1 ers sJightly from that of

I'

e pen to sans, for exam p le 'I'h ]"in fiber determination 1

.- .d i d. . 4. , elm It of error

'1 S WI e ,an not onl y a'

.but also !

, n the carb oh :I t ' "

ppears III the fiber itselfYl ra e extract (so call d .

t- 'II . ,d b

~

-. - e 111 rogen-free extract \oJ'. 1ese. ata ecome more re dil

"

. /

which i h . , Y comparable WIth my own anah'sesare! erem reported without fiber

determinations-.

- '

Samples, Ash, Protein F'New Hampshire

- . .'. . . . II

at. Carbohydrates

Vermont "'"I : .'5

7

9

C> 12.9b C>.1O79. [6

CII_lO 6.16 Sonnecticut q

1.73 11.75'-2 7

'T_I5

Pennsylvania "'"5 1. 55

. b1.25

N h 9.65 5 "7 1-\ort Carolina...,- - 2 1

- 50,;

3 . 13Kentucky..,.,., ,. I I .62 :;:,~: 5.-13 81.04

Tennessee.. .. . ..- "'"

I.5,77 Sl. 99

Indiana [1.33 10.05 5.5! 83.II

MI.44 [I . S4 0 0ichigan . . . . . . . . . . . . ..12

)- 49 "T . 23

1.67 12.8 _1Missouri. . . , . . . . . . . . . . . ? 6

5.70 79.80- , T.8 .3 II x

Kans~s - .4~ 5,75 Ko .94

Co]ortd~'_'.'.'.'.'- '-','- -.-. . '.'.'. '; i:.. ~~r [.53 5.53 8 [ .25

Texasi 20 10.95 1).32 81.05

Oregon 1.59II_6r 6.09 80_71

"" -. I 1.61 8_68Wash~ngton

-"" - "'"I

7.80 81. lJI

Mexic~.. .. . .. . .. .. 31.67 9.,6 6

-39 82. 581.75 rI.44 6.0680.75

CHEMTSTRY OF THE CORN hERNFL,135

Ca rbohydrateFiber. extract.

General average. . . . . . .1.69 II.6, ~o. (Jo

15, 'ro, ([876)

136 BULLETIN NO. 53. [Jut),>

The following are some of the conclusions which Richardson drawsfrom his data:

"There is apparently the same average amount of ash, oil, and albuminoids[protein] in a corn wherever it grows, with the exception of the Pacific Slope, where,as with wheat, there seems to be no facility for obtaining or assimilating nitrogen.

"Corn is, then, an entirely different grain from wheat. It maintains about thesame percentage of albuminoids under all circumstances, and is not affected by itssurroundings in this respect.

"Only two analyses have been made from the Pacific Slope and more areneeded for confirmation, but as the two analyses, like those of the wheats grownthere, are low in albuminoids, it may safely be assumed to be a characteristic of thatportion of the country."

These conclusions scarcely appear to be warranted from the data.By computation from the II 4 analyses of corn, I find the total varia-tion in protein to be 63.6 per cent. of the average amount determined;,while from the 260 analyses of wheat referred! to by him it is only neces.sary to exclude 5 analyses to bring the total variation in protein to 60. Iper cent. of the average amount determined. Or if we take the averages,of the 10 highest and the 10 lowest results on the protein of 114 samplesof corn, 12.34 per cent. and 8.19 per cent., respectively, we find the.difference, 4. IS per cent., to be 4° per cent. of the general average;while with the averages of the 25 highest and the 25 lowest results onthe protein of 26o samples of wheat, 14.97 per cent., and 9.28 percent., respectively, the difference is 5.61} per cent. or 48 per cent. of thegeneral average (11.95 per cent.). In other words the variation in thecorn is only one-sixth less than that in the wheat. It may be notedthat if we include the analyses of sweet corn (all varieties of wheat areconsidered) the variations in the protein content of corn exceed those inwheat. Jenkins and Winton's compilation2 shows the protein contentto vary more in 208 samples of corn than Richardson found in 260samples of wheat.

As to the assumption regarding the Pacific Slope it may be pointedout that the table of analyses from the different States shows the averageof 5 analyses of Pennsylvania corn to agree well in percentage of pro-tein with the single analyses from Oregon and Washington. The aver-age of 12 analyses of corn from California reported in 1884 by Richard-son3 shows practically the same percentage of protein as the general

average for the United States.In I 886 Flechig~ made analyses of 14 different varieties of corn,

lV. S. Depl. of Agr., Division of Chemistry Bulletin (1883), 1.

2V. S, Depl. Agr., Exp. Station Bulletin (1892) II, 100.3D, S. Dept. Agr., Division of Chemistry Bulletin (1884) 4,

4Landwirtschaftliche Versuchs-Stationen (1886) 32, 17.

-L~_~_.

-. ~-."".A

1898.J CHEMISTRY OF THE CORN KERNEL.137

all grorn under uniform conditions of weather soil and fe rti l ', t

.If we

r:'t

.f '

',IZa. Ion.ml a vanety 0 sweert corn I the following are his results:'!

i Variety. II

Ash Pt'Hune Hdtif d'Antonina'

,1'0 em. Oil. Carbohyrates,

Rother Hiihnermais.. r ..

'" ""I .29 12.63 5.40 80.68

Weisser steirischer ' ! 1 .43 II .06 5.80 80.71. "

1.51 IO.5° 5.32 826Weisser ungarischer . 7.

",,,,,,, 1.63 9.88 0.21 82 8C~nq.uat1no. . , .. .. .. , . .. ..

'". .. . .. , .1.48 9. 88 ~ ':2Turklscher vierzigtiigi ger

'

5.52 3., .. .. .. .. .. .. 1 .73 9.69 5.88 82

"'0Canadlscher aus Vngarn I. 58 9. So 6.00

8'

. I

BunteI' Augustmais 2.92.. . , . . , . . . . . . . . . . . , , 1 .44 9.50 5.02 84 04

Fruh. Amerik. Bernsteinmais I 2 .

Friiher Badischer "'",..' .4 9.19 5.75 83.64...1.46 906 5.43 8Blanc hdtif des Landes

1 6'4. aS

Improved King Philipa 9.00 6.22 83.18

P,+pageienmais.,.,.. .'.'.','.'.""""'" ~'53

4

5

8.95 5.43 84.08

i .""""". 8,69 5.88 84.08

. I~ iv.iew of the ,fact that r~ference has already been made to thewIde hIflt of. e~ror III fiber determinations, it may be noted here that

the tot:U vanatlOn on th fi I I flena resu ts or fiber as reported b y Flech'on the iI3 sam p les of .f

Ig. corn IS rom 1.2' per cent to 8

6whil th ". .). 1. per cent"e ,e vanatlOn III the separate determinations made on a single

sample IS from I 26 Per c tt 8 ..

"'..

en '; 0 1. 3 per cent. It IS also observed thatFlechlg ~results Illdl~ate pro,tein as the most variable constituent ofcorn grtwn under ullJform conditions.

, Sin~e the establishment 'of the experiment stations in the United?tates ti

~nU~ber of proxiljUate analyses of corn has been greatly

Increase,(j'; but 1ll.the main the analyses have been made for special pur-poses (ah III feedmg experiments) other than a study of the corn itself

an~ up~, ~amples whose history was unknown or unnecessary for th:ob.Ject m vle~. Only one series of these analyses will be discussed inthIs connectIOn,

In 1893 the Connecticut Experiment Station published~ the analysesof 9° sampl~s of corn grown in 1892 in various parts of the state fromabou: .75 dIfferently named varieties, and under exceedingl y varyingcondItions of weather, soil, cultivation, fertilization, etc. If we omitone sample ~t sweet corn, and one sample which was injured by hailbefore matunng, the following are the five highest and the five lowestresults from all determinatioI?s of each constituent; also the generalaverage $f all analyses: I

~..~-!

I Suc~e ride.

.2 A f~w errors were found in Jflechig's summary which I have corrected from

his analytJpal data. Fiber is inc1ud~d in the column headed carboh t

3Especially by V S D f . yra es.

N. J... , ept.o Agr. and Stations of Conn" Mass, Ill., Vt. a.nd

'Conr. Agr. Exp Station Annual Report (1893),Ir

138 BULLETIN NO. 53. [Ju~y,

Ash

1st highest , .." 2. 10

2nd . . . , . . . . . . . , I .90

3rd . , . . . . . . , . .'

. I ,86

4th'

, , .'

. . . , . . . . I .80

5th . . , , . , . . . . . . . I .79

Protein.

14.53

14,°413.86

13.33

Fat

6.39

5.97

5.95

5.955,95

Carbohydrates.

85.93

85. '485.°784.67

84.6313.29

1st lowest., , .9'

2nd . . . . . , . . . . , .. .98

3rd . . . . . . . . . .. . I .004th I.OI

5th . .. .. .. .. .. .. I ,°4

8.338.69

8.798.82

8,25

,78.56

78.85

78.99

79.26

79.85

3. 'S3.554,21

4.28

4.31

General average..., 1.39 II ,6j 81. 7 I5.27

The compilationl of Jenkins and Winton gives the average compo..

sition of dent and flint corn as follows;Protein. Fat. Carbohydrates.

II.5 5.6 81.211.8 5.

(, 80.9

11.6 5.6 81.1

By mechanical means the

corn kernel has been separatedinto four different parts. Thesemay be designated (fig. 1") as

Ca) the coat, or hull, of thekernel, (b) the hard glutenouslayer ~nderneath the hull,much thicker at the sides thanat the crown, (c) the chit, orgerm, and Cd) the starchymatter constituting the chiefbody of the kernel. It hasnever been found possible tomake such a separation witheven approximate accuracy,the separation of the glutenouslayer from the starchy portionbeing especially difficult. Onthis basis Salisbury" gives thefollowing percentage composI-tion of the kernel with theFIG, 1.

h i b.

proximate composition of the different parts reduced to t e (ry aSlS:---~S. Dept. of Agr., Exp. Station Bulletin (1892) II,

"I am indebted to Director Voorhees, N. JAgr. Exp. Station. for the use of

this cut."Trans, N, Y. State Agr. Soc (1848) 8. 671L

Samples

Dent. . . . . . . . . . . , . .' 86

Flint. . . .'

. . , . . . . , . . ."

68

General average. . , . , . . . 154

Ash

1.7

1.7

1.7

~

JlIl I.

1898,J, CHEMISTRV OF THE CORN KERNEL 1,)9

",Glutenous Starchy

I, Hulls. layer portion. Germs.

~ercent ,4.(° 66.63 18.04 II..Oj

~sh 4.;56 ,43 .61 14.05

Protein'.. . ' 7.65 7 .74- 21.39Oil. .. . . . . .. .. .. .. . .. . 2.87 3, °7 3°.26C~rbohydrates2. . . . ., , 89. °S 93.58 34,30

In' a microscopic study of the corn kernel Haberlandt" observed thatthe germ contained a large amount of oil while in the remaining por-tions of the kernel no oil was apparent. Acting upon this Lenz'l under-took an analytical investigation of these portions. The germs werecarefully removed from the kernels by mechanical means and the oil andprotein in the two portions determined. His results on a sample ofAmerican white flint corn are as follows;

Kernels less germs.Per cent, . . , . .

'. . , . . . . . . . . . ., .. 88. IS

PercentOil<""""""""""'"

1.57,'j

, . Protein' . . , . . . . . . . . , . . . . . . . . 13. °9

C;-erms.

IJ.~2

F.83

19.93

Lenz expressed the opinion that the small quantity of oi 1 found inthe kernel after the germ had been removed was really due to particlesof the ghm which had not been removed or to traces of oil depositedon the rymainder of the kernel during the mechanical process of remov-ing the germ.

Thip was furtber investigated by Atwater'; who removed the germtogether', with a considerable portion of the kernel immediately sur-rounding the germ in order to insure the separation of all oil properlybelonging to the germ. Following are his results,

Ou ter portion

free from germ.

Per 'cent. . . . . . . , . . . . . . . .. ,...76.43Per cent. Oil4..., ..

'" ", . ,. ., .. '. r .63

Inner portion

including germ.

23.57

Recently Voorhees" and Balland' have published the following re-suIts,

Hulls.5.56

12,4°

Glutenous layer

and starchy portion.

84.27

74, ro

10.17

13.50

Voorhees.

Balland.

G.erms.

'This is given here as the surn of the zein. albumen. and casein reported bySalis bury.

2By d,ifference, ,

3Allg~meine land- und forstwirtschaftliche Zeitung (1866) 257 Jahresberich t

[Hoffmann1 uber die Agricultur-Chemie (1866) 9, 106,4In tHe dry matter, ,

"Thesis, Yale College (1869); Atnerican Journal of Science and Arts (1869) 12]

48,352. II

GNew',Jersey Agr, Exp. Station Bulletin (1894) 1057r ~+-- --- ~u

-,

J4°

The(dry).

CarbohydrateAsh. Protein. Oil. Fiber. extract.

Hulls. \ 1.25 6.52 1. 57 16.24 74.42 Voorhees..( 1.44 8.20 l.33 11.25 76.78 Balland.

C;lutenous layer and

{

.68 12.15 1.53 .65 84.99 Voorhees.starchy portion. .68 8.53 1.08 .40 89.31 Balland.

\ 10.02 19.54 26.65 2.59 41.20 Voorhees.Germs. 1 7.87 15.32 39.85 Balland.1.99 34.97

BULLETIN NO. 53. [ JIIly,

following table shows the compositionl of the separate parts

These data confirm the earlier results, showing the germ, whichconstitutes only about 12 per cem. of the kernel, to contain nearly twiceas much mineral matter and three or four times as much oil as all of theremaining portions of the kernel. It is also rich in protein. Voorheesstates that the portion richest in protein is the glutenous layer.

In the manufacture of starch and glucose-sugar from corn thesedifferent portions of the kernel are separated much more perfectly thanit is possible to do by hand although their original composition is some-what altered. Various methods2 have been employed, but the followingwill indicate briefly a common process:

The corn is steeped in warm water containing a little sulfurous acidand then reduced toa coarse powder. The germs together with a partof the hulls are recovered by floating and separated after drying. Thematerial remaining in the water in suspension is passed through sievesand the remainder of the hulls and some other coarse matter can thus beseparated from the starch and the more finely divided gluten. Thestarch is finally allowed to settle and then the water containing the largerpart of the gluten is run off. After further purification the starch is soldas such or is manufactured into other products, as glucose-sugar. Theby-products. hulls, "gluten," and germs, separate or mixed, are sold asfood stuffs, the larger part of the oil usually having been expressed fromthe germs. The mineral matter is, of course, largely removed fromthese products by the solvent action of the water.

The analyses of corn oil cake was reported3 by Moser as early as1867 with the following results:

CarbohydrateAsh. Protein. Fat. Fiber. extract.8.07 17.19 12.58 1I.41 50.75

The following is believed to fairly represent the composition (dry) ofthe several individual products, not as usually found on the market butin their purest condition:-----IAs published Voorhees' results are evidently given on the basis of ash-freeorganic matter. They are here calculated to the basis of total dry matter.

2Journal Society Chemical Industry (1887) 6. 84.3Jahresbericht (Hoffmann) liber die Agricultur-Chemie (1867) 10.259. Cf. ibid.

(1872) 15,21; (1874) 17. IS; (1876) 19. IS.

" ~

I898.Ji CHEMISTRY OF THE CORN KERNEL.141

Ash.Carbohydrate

Protein. Fat . F ' bHulls' 'er. extract.

Gluten;""""""1.02 11.18 4.13 Il.g8 71.69; .1.14 44.°3 7.69 2.26 44.88Germ cakel 8

Starch"2.5 27.23 14.84 7.41 47.94

I 0.3° "" 00... 99.704

Tije correctness of Voor~ees' statement that the t'f hkern 1 r' h t" por IOn 0 t e corn

e'bIC

es ,,1Il protein is th!e glutenous layer is plainly apparent.

h.RI! hards has recently Ifade proximate analyses to determine the

eatmg v~lue of the corn kerl)el. Calorimetric determinations were alsomade, bemg reported in ter~s of the British thermal unit" FoIl' .

are the results: . owmg

Moisture.Yellow dent .8.45White dent .8.88

Volatilematter.78.1077.22 12.90

Fixed

carbon.

I2.IRAsh.

Fuelvalue.8202.8338.

r.271.00

EXPERIMENT AL.

totalI~

the following work on the proximate composition of corn the

. ? matter, th~ ash, the nitrogen, and the fat were determineddlrectlY1 The protem was esrimated by multiplying the total nitrogen

b~ 6.25 land the carbohydrates by subtracting the sum of the ash, ro-tem, an~ fat from the total dry matter In h'

I d . p.f tl ' I . . . eac smg e etermma tJOn

°t k1e sFvera cons~ltuents 2 g-ms. of air-dry substance were reO'ularl

}'a 'en. ; b

PRE:PARATIO.N OF ~AMPLE.-AII samples were air.dried, ground topass thr?ugh a sIeve wIth circular perforations I miIlimeter in diameter

and the~. preserved in air. tight vessels, being thoroughly mixed -us~before b~rng analyzed. . ' J

DE1]ERMINATION OF DRY MATTER Th . :J b.I I

. ". - e alr-l ry su stance was placedm ~g as~ tube 10 em. long and 12em. in diameter over one end of which.a pIece qf .hardened filter pap~r had been firmly tied with nickel wire

the tube :wlth pa~er bottom having been dried and weighed in wei hin'tubes before berng charged with the substance Th

'b

g g

d,' d 'th h b . . . . e su stance W3.SlIe WI t e tu e Iyrng III a horizontal position in a current of dr

hydrogen at a temperature of J05° maintained bb

.1'

Y

I t' f I 'y a 01 Illg aqueousso u IOn 0 g ycerol in a double-wall bath provided with

tde Th a re urn con.nser. e gas entered the bath at one end near the top and assed

~~t at the bottom near the opposite end. p

IN. J. Agr. Exp..Station Bul. (1894) 105.2Conn. Agr. Exp. Station Report (1895) 231.

"Jour~al Society Chemical Indl1stry (1887) 6, 84..Starc!:h. ;

:U. SI Dep~. of Agr... Exp. Station Bulletin (1898) 49,95.Hea, requIred to raIse one pou?d of water from

50° to 51° F.

142 [.f/lry,BULLETIN NO. 53.

To determine the error in obtaining the weight of the empty tubeswith the paper bottoms, 10 tubes were dried for one hour, cooled indesiccators and weighed in weighing tubes, then dried again for twohours and again weighed, with the following results:

First weight. Second weight. Decrease.I...

""""""'" .47.7552 47.7550 .0002

2 .49.0332 49.0328 .0004

3 46.1074 46.1074 .0000

4 .48.9842 48 9843 -.0001

5 .: 48.6642 48.6641 .00016.. . . . . .. . . . . . . . . .. .. . . . . 45 . 450 I 45 . 4500 . 000 I

7. . . . . . . . . . . . . . . . . . . . . . . .48.5461 48.5455 . 00068. .. .. .. . . .. .. . .. .. .. .. .. 47 . 85 I 6 47 . 85 I 8 -~ .0002

9 ..,.. , .44.8934 44.8930 .000410.. .. .. .. .. . .. .. .. .. 46.2726 46.2727 -. 0001

To determine the length of time required under the conditionsmentioned to reduce the substance practically to a constant weight thefollowing data were obtained, 2 gms. of air. dry substance being takenfrom 12 different samples:

Difference in weight

between drying

4 or 8 8 or 164 hours. 8 hours. 16 hours. hours. hours.

1 1.7759 1.7639 1.7600 .0120 .0039

2 1.7662 1.7545 1.7512 .oIl7 .0033

.3 1.7569 1.7454 1.7413 .OIl5 .0041

4 1.7638 1.7525 1.7489 .oIl3 .0036

5 1.7662 1.7550 1.7513 .OIl2 .00376 1.7635 1.7520 1.7483 .oIl5 .0037

7 1.7589 1.7476 1.7435 .OIl3 .00418 1.7651 1.7541 1.7503 .0IlO .0038

9 1.7738 1.7625 1.7580 .Olr:) .004510 1.7536 1.7422 1.7387 .0114 .0035

II 1.7623 1.7505 1.7457 .oIl8 .0048

12 . .. . I .7556 1.7450 1.74Il .ow6 .0039

After drying 4 hours the average decrease in weight for four hoursmore is 0.OIl4 gms. or 0.6 per cent. of the amount determined, andthen for 8 hours more it is 0.0039 gms. or 0.2 per cent. of the amountdetermined. This is a much narrower limit of error than can be main-tained in the determination of the constituent groups of the dry matter,.and all dry matter determinations which follow were made by dryingthe substance 8 hours. It is noteworthy tbat during the second andthird periods of drying all of the samples lost weight and in very nearlyequal amounts, showing that for comparative results a very high degreeof accuracy is attained.

The following work was done to test the agreement of duplicatedeterminations on the same sample. Twelve different samples wereselected, and the 24 portions of 2 gms. each were all dried together:

Weight of substance after drying

[898.J CHEMISI'WV OF THE CORN KERNEL.[.J..1

Weight of dry

matter. Variation

'. ..1.8276 1.8273.00°3

2. . .1.8230 1.8238 .0008

.3. ..1.8218 1.8222 .0004

4 1.8319 1.8314 .00055. I ..1.8244 1.8249

.00°56 1.81g8 1.8194 .0004

:. j.. 1. 8264 1 .8267 . faD] Average.. .. .. .. .0.00.5

}r9m these results and those preceding it is seen that determina-tions mtde in the same bath [and at the same time show a remarkabkdegree tf accuracy when cOI~pared only with themselves, and among,themseIyes they are strictly c(?mparable.

To 'rletermine the variatidm which might be caused by unavoidablediffe~ences in te~perature, hydrogen current, etc., the follow iug 36dupltcate determmations of dry matter were made, in every case theduplicate determinations being made at different times, i. c.. the Firstdetermination on each sample was made one or more days p~evjol1s tothe second, or duplicate, determination:

Weight of dry

matter0 ...I.8240 I S242

9....J .8243 I .824010. .I.8202 1 8209

11....1.8176 I.KIH6

Variation

.000'2

.clOO 3

.00°7

.001012. . . . .f . :)15° f. :)155 .00°5

Weight of drymatter.

Weight of drymatter.

20.. .. 1. 7566

21 [.773°22. . . . I .7795

23. . . .1.7668

24 1.7584

25 1.756026... 1.7431

27 ...1.752628. . . . 1.7540.

29. . . . 1 .7590.

.1°...1.749431 ... ]

.7489j2 .. .. 1 .7498

33 1.7552.14. . . .1.7925

35 1.751536 .. 1.7451

VariatiDnVariatiDn1.. .1.7456 1. 7489 .00.33

2.. .1.7493 1.7527 .0034

3.. .1.7444 1.7441 .DfJD3

4.. .1.7362 1.7360 .0~02

5.. . I.7200 1.7238 .00386.. .1.7514 1.7541 .0.927

7.. .1.7675 J.7689 .0<;>148.. 1.7628 1.7637 .0.00.9

9 1.7659 1.7673 .0.014JO...i.I.7540 1.7588 .0048rr...1.1.7522 [,7547 .0025

12.. ..1.7554 1.7592.0°38

13. ..~1.7698 1.7739 .0~4[

I4...f1.7546 1.7586 .0.040.

15... I 7691 1.7741 .D~5016... 1.7552 1.7573 .OO~I17... .7723 1.7689 .00[3418... 1.7736 1.7696 .00.40

'9.. ..1.7760 1.7742 .oar 8 Average .0027

The maximum variation 0.0082 is 0.5 per cent. of the average

amount determined; and is very much greater than when the duplicates

were made at the ~ame time. However, the agreement still appears

very satisfactory. In all subsequent work herein reported the duplicate

determinations of dry matter were made at different times in orJ er that

the results may show the widest variations possible with the method

employed.

DETERMINATION OF ASH.-The air-dry substance was placed in a

1.7520

1.7719I . 77341.7593

.0.°46

.0011

.0061

.0.°75

.0082

.0026

1.7502

1.7534

1.74.351.7540.

1.7539].7599

1.7512

1.7465

l.7497

1.7559[.7928

1.7481

1.7400

.OOO{

.001+

.0001

.0.00.9

.0018

.ODL!

.0001

.0.0.07

.000.3

.00.34

.0('43

144 BULLETIN NO. 53. [July,

porcelain crucible and burned to constant weight in a muffle at a low redheat, at a temperature below that at which portions of the ash wouldbecome fused and attached to the crucible.

DETERMINATIONOF NITROGEN.-This was made by the ordinary Kjel-dahl method. The metallic mercury used in the digestion was measuredin a capillary tube, one end of which is doubly bent so as to form aloop, the short arm of which is turned back upon itself near the endwhile the long arm serves as a handle. The loop is made sufficientlynarrow to pass into the mercury bottle, and of sufficient length to retainwhen raised above the liquid the exact quantity of mercury required fora single determination. By blowing in the longer arm the mercury isemptied into the digestion flask.

Heavy copper flasks were used in the distillation with much satis-faction, the sodium hydroxid solution (containing the necessary amountof potassium sulfid) being added in sufficient excess to "bump" beforethe contents may become dry, thus serving as a signal that the distilla-tion has gone far enough.

Two common sources of error in the nitrogen determination werefound and investigated. In titrating an acid solution in an open vesselwith standard ammonia solution a very appreciable error is introduced'by the volatility' of the ammonia, although the only possible loss is

from the tip of the burette and from the falling drops.In the following work ammonia of about one-sixth normal strength

was used, the hydrochloric acid being of such strength that 3 cc. wereequivalent to approximately 4 cc. of ammonia. The hydrochloricacid was measured from an automatic overflow pipette of IS cc. capac-ity, and the ammonia from an automatic overflow burette graduated to

0.°5 cc. and drawn to a fine tip at the outlet. The pipette and burettewere each provided with three way stopcocks through which thestandard solutions were drawn from the stock bottles by means ofsyphons. Perfectly neutral water free from ammonia and carbon dioxidwas used for diluting. Lacmoid served as the indicator and gave anexceedingly sharp end reaction.

By titrating in beaker flasks with the tip of the ammonia burettewell below the top of the flask the following results were obtained, thelength of time taken in making the titration being also given:

I , IS ee. HCl required 20.10 ee. NH3.-time = I minute.

2 1see. HCI 20.08ee. NH3,- .. = I

3 ...lsee. HCI 20.12ee. NH3,- .. = I

4 1see. HCl 20.30ee. NH3,-.. = 2

S lsee. HCl 20.2see. NH3.-.. = 2

6 .IS ee. HCI 20.40 ee. NH3.- .. = 3

'Rempel has already shown that dilute ammonia s?lution drawn into beakers orevaporating dishes and then titrated suffers marked loss.-Zeitsehrift fur angewandte

Chemie (1889) 331,

1898.] CHEMISTRY OF THE CORN KERNEL.145

By titrating in an Erlenmeyer flask attached to the burette by means{)f a rubber stopperI, provided with a capillary tube for relieving thepressure1 the following results ,were obtained:

I. '; ."'"

. . . IS ee. HCl required 19.82 ee. NH3.-time= I minute.

2..\ IS ee. HCI t' 19.83 ee. NH3,- ..= I

3"I 1S ee. HCI 19.81 ee. NH3,-" = 34 '1 15 ee. HCI .. 19.81 ee. NH3,-" = S

As from 3 to 5 minutes are taken to make a titration when theamOl~nt ~f ammonia required is not known, as in ordinary nitrogen de-termmatl,ons, the error2 from titrating in open vessels becomes an im-portant ffctor, the total variation. in thetwo series of experiments abovenoted amlounting to 0.6 cc. or $ per cent. of the ammonia required. Thefact that ~he density of ammonja gas is but little more than half that ofair expla~ns its rapi.d u~ward djffusion from an open vessel.

.Ano~her error m n~trogen feterminations may occur in the distilla-

tIOn by lpss of ammoma from, the receiving flask in case there is notsufficient 'acid above the end oj'the delivery tube to neutralize all of theammonia distilled over.

In the following work a qU1\.ntity of a very dilute solution of am-

moni~m c~lori~ was prepared by exactly neutraJizing standard hydro-chlonc aCid wIth standard ammonia and diluting with ammonia-freewater. A quantity of this solution equivalent to 12 cc. of standard am-monia was placed in a distillation flask with an excess of sodiumhydroxidand distilled into I5cc. of standard hydrochloric acid dilutedto ab~ut40 cc". the end of the delivery tube from the condenser dippingwell./tlIO

te.acui solution.

, The relation of the standard acid and am-mama s~ ,utl~n: wa~ such that IS cc. HCl were equivalent to I9.82 cc.NH3' SIX dIstIllatIOns were made, in each case ammonium chloridequ!valen~ to 12 cc. of standard ammonia solution being taken. Fol-10wlDg

.a~e the amounts of st,mdard ammonia solution required to

neutraltze,the excess of acid:

Req\1ired.I. . .. 8.20 ee.2. . .

'1'. . . . . . . . . . . . . . . . . . .7.8:5 ee.

3. . .'1'

. . . . . . . . . . . . . . . . . . .7 . 9~ ee.4. . . . !.. . . . . . . . . . . . . . . . . . .8. 6d ee.

5. . . . l . . . . . . . . . . . . . . . . . . . 7 84: Cc6 1

. ! .. . .

'1'. . . . . . . . . . . . . . . . . .7.

9s1 ee.ITwo I,Jf these are practicaqy exact, the other four showin

g errors. f I Ivarymg rom 0. I 1 cc. to o. 78 ce. of standard ammonia.

This work was repeated with the distillation from quantities of am-

monium chlorid equivalent to IS c~. of standard ammonia solution, the

lBy using a stopper which has heen hored nearly through from the small endby a large borer, the flask may easily be given a free rotary me.lon.

.Confirmed by recent (unpublished) work of Dr. F. L. Kortright.

Calculated.7.~2 ce.7.82 ee.7.82 ee.7.82 ce.7.82 ec.7.82ec.

Error.

0.38 ce.

0.03 ce.o.It cc.

0.78 ce.0.02 cc.

0.13 ce.

]46 BULLETIN NO. 53. [Jury>

other conditions being as before. Following are the amoUnts of stand-ard ammonia solution required to neutralize the excess of acid:

Required.I. . . . . . . . . . . . . . . . . . . . . . . .6.10 ee.2. . . . . . .. 5.40 ee.3. .. .. . . .. .. . . . .. . .. . .. . .5.9S ee.4. . . . . . . . . . . . . . . . . . . . . . . .6.20 ee.5. . . . . . . . . . . . . . . . . . . . . . . .5.65 ee.6. . . . . . . . . . . . . . . . . . . . . . . .5.18 ee.

Calculated.4.82 ee.4.82 ee.4.82 ee.4.82 ee.4.82 ec.4.82 ee.

Error.1.28 ce.0.58 ee.1.13 ee.1.38 ce.0.83 ee.0.36 ee.

Diluting the residues in the distillation flasks with ammonia-freewater, and distilling, gave no further addition of ammonia in any case.

It was observed that in both trials the greatest errors occurred withNos. I and 4. A careful inspection of the apparatus showed all con-nections to be perfect. It was observed, however, that the deliverytu bes from Nos. I and 4 did not reach as far into the acid solution asmost of the others.

With the thought that possibly ammonia escaped from the receivingflasks, the following six distillations were made, in each the quantity 0 fammonium chlorid employed being equivalent to 19.32 cc. of standardammonia solution; thus, exactly 0.50 cc. of standard ammonia should.have been required to neutralize the excess of acid. Somi lac maid in-dicator was added to the acid solutions in receiving flasks Nos. I, 3,

and 5; strips of moistened red litmus paper were also hung in the necksof these flasks. During the process of distillation, receiving flasks 2, 4,and 6 were agitated to keep their contents thoroughly mixed.

It was observed that, during the process of distillation, in receiv-ing flasks I, 3, and 5 the liquid above the end of the delivery tube turnedblue, while a layer of liquid below this remained .red; also that themoistened red litmus paper hung in the necks of these flasks turnedblue.

In titrating the excess of acid the amounts of standard ammoniarequired were as follows:

Required.I . . . . . . . . . . . . .. . . . . . . . . . . 2.60 ee.2 .. .0.5° ee.

3 . .. 2.27 ee.4. . . .. . . . .. . . . . . .. . .. . . . . 0.53 ee.5. . . . . . . . . . . . . . . . . . . . . . . . 1.99 ee.6. . . . . . . . . . . . . . . . . . . . . . . .0.5° ee.

Calculated.0.5° ee.0.50 ee.a .5° ee.0.5° ee.0.50 ee.

0.5° ee.

I .77 ee.

0.°3 ee.1. 49 ee.

0.00 ee.

Error.

2.10 ee,0.00 ee.

The explanation for the separation of the liquid in the receivingflasks into two layers as described is to be found in the differentdensities of aqueous solutions of ammonia and hydrochloric acid.

In subsequent work I have used delivery tubes reaching to the verybottom of the receiving flasks, and contracted at the end to an apertureof but 4 or 5 mm. diameter. This insures considerable agitation of the

l'] ..

1898. ] CHEMISTRY OF THE CORN KERNEL.147

content of the receiving flask produced by irregularities in the boilingof the liquid in the distillation flask.

This loss of ammonia shown to have taken place from thed'l t If' h

veryI u e so u IOn. m t e receiving flask after cooling by an efficient can.

den~er ~mphaslzes the results of the preceding work on titration and'the Imp~>rtance of avoiding a porn man error in that process.

DE'4ERMINATIONOF FAT.-lThe glass tube with the bottom of haIdenedfilte~ pafer (previously described) containing the dry matter from 2 gms.of alf-dlY substance was placed in a Soxhlet tube and the fat extractedthe solv~nt p~ssing through th~ su?stance and being filtered by the pape;bottom. I ThIs arrangement is for several reasons preferred to the useof tubes!made entirely

.of filter paper. 1. The determination of dry-matter tnd the extractIon o£ fat are done in the same tube withouttransferrlmg the substance. v The solvent must pass through the sub-sta~ce. :3. Th: ha~dened paper can be removed from the tube (aftertakmg

of the WIre hg~ture), s~read out in the side of a funnel and thefat-free iubst~nce e~sIly and cpmpletely removed from both paper andtube, by iwashmg wIth the hotldilute sulfuric acid to be used in case afiber determination is desired.

'The ethe~ used in the extraction was kept over metallic sodium in

the form of WIre, and redistilled before being used. The upper end ofthe condenser was protected by a calcium chlorid tube.

Mainly to avoid the constant trouble of havingatmospheric moisture condense upon the outer sur-face of a Liebig or Allihn condenser and run downOver the extraction apparatns, the following formof condenser (fig. 2) was designed;

This: condenser is made entirely of glass, andconsists 9f a tltin glass tube (a) 25 mm. outsidediameter land 25 cm. long, provided with two gla:=stubes about 6 mm. in diameter, one reaching tonear the bottom of (a), sealed in for water inletand outlet. The tube (a) is surrounded by astronger glass tube (b) of 30 mm. inside diametersealed on, at the top and narrowed at the lowerend to a 10 mm. tube which extends 8 mm. belowand is grdund off obliquely at the end. About

3em. from; the top of tube (b) a side tube (c) is.p~ovided;

I

it is:5 c~. long and 12 mm. inner

i dIameter, Iand IS wIdened, as indicated in theFi~. 2. figure, where it is sealed into (b). The water

tubes are cut off at a length'of 5 em., being blown as indicated to holda rubber tube.

The outer tube of this. condenser is not cooled to a temperature at

. .

'148 BULLETIN NO. 53. [Jury,

which atmospheric moisture will condense upon it. This is its chiefadvantage over the ordinary form in fat extraction with anhydrousether. The side tube serves to connect with a drying tube.'

In making the proximate analyses which are reported herein the fatwas always heated in a current of dry hydrogen for 3 hours at 1°5°;the flask allowed to cool in the air and then to stand in the balance caseuntil the weight became constant. The flasks used in the work were ofErlenmeyer's pattern with about 100 cc. capacity and weighed 25 to 3°gms. each. Differences of barometric pressure and of humidity of theatmosphere of the laboratory may easily produce slight changes in'weight.

To cool the flasks in desiccators before weighing was found unsatis-factory on account of the fact that the perfectly dry air of the desic-,cator is considerably heavier than the moist air of the laboratory, andafter the flask is removed from the desiccator its weight does not becomeconstant until the dry air is replaced by that of the laboratory and the,condensation of moisture upon the surface of the glass ceases.

In all of my analyses herein reported to determine the proximate'composition of corn, two complete single analyses were made; thecomputations were made separately with no averages, and the results'are reported separately. Furthermore the two analyses were made at,different times, and the differences between the duplicates certainlyfairly represent the experimental error. The computations were madeby logarithms and directly to the percentage composition of the dry matter

The logarithm of 6.25 was included in the proper factor logarithm forcalculating the protein equivalent from cubic centimeters of standardammonia solution. In no case has the percentage of nitrogen or thepercentage composition of the air-dry substance been calculated. Ifdesired the former can be determined exactly by dividing the percentage

'A few other important points may be noted. The condenser may be used inordinary distillation by passing the vapor in through tbe side tube. The ordinarycondenser frequently breaks in consequence of tbe extreme differences in tbe temper-ature of tbe inner tube just above and below the surface of the surrounding water.The new form is free from this objection. The water tubes are both at the top andvery convenient for joining up a series of condensers. These condensers are morecompact and yet mucb more effective tban the ordinary form, the vapor being dis-tributed in a thin layer over a very large condensing surface. the outer tube alsoacting as an "air condenser."

Tbese condensers have been in almost constant use during the past year in thechemical laboratories of the University of Illinois and have given excellent satis-faction.

There are several condensers which have the water tube inside, but I havefound none suited to the purpose for which this was especially designed except thatrecently described by Sudborougb and Feilmann (Jour. Soc. Chern, Ind. (1897) 16,979), which is certainly to be preferred to the ordinary form as a return condenser.,though it cannot be used safely in distillation.

1898. I CHEMISTRY OF THE CORN KERNEL.149

of protein by 6.25. The fact that the moisture content of air-dry corn

mere~y depends upon the weather and is just as changeable is deemedsufficIent r~aso~ for ignoring the percentage composition of the air-drysubstance In thIs study.

COLLECTINGSAMPLESOF CORN.-To determine the accuracy of takings~mples of corn a bushel or more of shelled corn from each of tendIfferent lots was thoroughly mixed, and then two samples of one pinteach were take~ for analysis, a single analysis being made of eachsample. FolloWIng are the results obtained:

Carbohy-'drates.83.8083,66

83.3183.41

AsblI

I\ I. 4~

i 1.4i

2j 1.4~I I.4~

Protein.

ro.0710.19

Protein. Fat.

II.04 4.6610.81 4.63

Carbohy-drates.

82.8283.n

Fat.

4.714.73

4.434.40

Ash.

6 JI. 48

/1.45

7JI.50/1.49

10.8510.78 ".33

II.43

II.3511.42

4.794.77

82.3882.3.1

3 J

Ir

"

443~

10.72 4.2483'

,

61/

JI

10.66 4.25 83.66

4 ~1.50j 11.40 4.44 82.,66(1.53j 11.42 4.49 82.156

, ,

5J 1,48, 11.24 4.73 82.155

{iI 471'

11.04 4 73 8 16 ro '.49 11.09 4.73 82.69,

.2'7 1.48 11.02 4.73 82.77

. ~hese results show the method of sampling to be satisfactory. ThevanatlOn~ between results on duplicate samples are scarcely greater thanthe expenm~nt~l error in making duplicate analyses of a single sample',

~It~o~gh van~tlOns among the different lots amount to very much more.fhls IS especlal.ly marked in the fat column where, although the average

amount determIned is less than5 Per cent there i d ' ff., s a I erence among

the lots of from 4.25 to 5.15 or0.9° per cent. and between duplicate

samples of only 0.°5 per cent.ANALYSESOF ON~ VARIET\'. 2--The following ten duplicate analyses

we~e made to determIne the possible variation in a single variety of corDwhIch hadl been gr?wn under conditions as nearly uniform as possible.From each, of ten dIfferent tenth-ilcre plots lying in the same field severalbushels of !corn were taken. The corn was shelled thorou

g h] .dand' t' I k f '

, y mlxe ,a pm jsamp e ta en rom ef\ch lot for anaylsis. Following are tbe

results obt~ined: .

: Carbohy-C b hAsh. I Protein. Fat. drat es A h . ar 0 y-

, . s. Protein. Fat. drates,I

~ ~:~i 1 ;;:~; :::~ ~;'~i 3J ;' 3

3~11.1(

89 4.27 83.21

I . : /. I I. 0 4.27 83.29

2~

1.42

~

III.54 4.45 82.59

J 1.49 11.47 4.38 82 66_~3 11.50 4.47 82.6~ 4/1.50 II.41 4.30 82:79

'See th following table. j2A vari tyof wbite dent corn wkll known in Illinois as Burr's Wh'

t Th -co n h b .I 1- 1 e. IS: as. ee

bgrown 1Q arge quantitie~ for several years upon tbe.University of 11li-

nOls Ag~lCUlt, ral Ex~er~ment Station fij;Jlds, and special precautions have been takeDto keep It pure and d,stmct.

8 J 1. 5I

/ 1.54

9 J I. 43I 1.43

5.145.15

4.764.81

82.00

81.89

82.7°82.67

II. IIII .09

'ISO

Ash.

5\ 1.34I 1.34

6 J 1.38( 1.42

7 J 1. 41i 1.38

Protein. Fat.II . 26 4 . 49II.24 4.47

II .62II.70

11.42

II.33

BULLETIN NO. 53.

4.444.41

4.364.39

Carbohy-drates.

82.9182.95

82.5682.47

82.8182.90

Ash.

8 J 1. 42

I I. 41

9 \ 1.39i 1.39

{I.42

101.42

Protein.

I I. 49II .44

11.56II .51

11.47II .45

[JIIly,

Fat.4.264.30

Carbohy-drates.

82.8382.85

82.5882.55

4.474.55

4.424.48

82.6982.65

These results show a marked degree of uniformity, seen more.clearly from the following maxima and minima of all determinations:

Ash.Maximum .1.50Minimum. . . . . . . . . .. .. 1.33

Difference. . . . . . . . . . . . . .0.17

Protein.II.70II.08

0.62

Fat.

4.554.26

0.29

Carbohydrates.

83.29

82.47

0.82

By referring to Flechig's experiment (page 137) it is seen that with

thirteen different varieties of corn grown under uniform conditions he~btained results showing the following variations:

Ash. Protein.Maximum.. . .. . .. . .1.73 12.63Minimum 1.29 9.00

Difference """" .0.44 4.63

Fat.

6.22

5.02

1.20

Carbohydrates.

84.0880.68

3.40

ANALYSES OF DIFFERENT EARs.-In order to investigate more fullythe question of variation or uniformity in a single variety So separate ears-of Burr's White corn from the same field as that used in the preceding-experiment were carefully selected from a number of bushels which hadbeen especially picked out for seed corn. The 50 ears were all wellformed and well matured, and had been grown in a field which had beenselected because of its uniform soil conditions. Duplicate analyses weremade of the corn from each ear. Following are the results obtained:

Ash.

1 J 1.44i 1.46

2 J 1.60I 1.60

3 J 1.32I 1.29

J 1.264 ( I. 26

J 1.095 I 1.10

.6 J I. 34i 1.32

7 J I. 30( 1.28

Protein.

10.79IO.86

12.7712.84

IO.77IO.76

10.4910.46

9.339.27

9. II9.13

10.4110.41

Fat.

5.665.65

5.195.22

4.164. II

4.534.54

4.354.41

4.064.13

4.194. IS

Carbohy-drates.

82. II82.03

80.4480.34

83.7583.84

83.7283.74

85.2385.22

85.4985.42

84.1084.16

Ash.

8J 1. II( I. IO

9 {1. 411.42

10 J 1.44! 1.43

II J 1.54i 1.56

12j 1.39

I 1.38

13 J 1.37( 1.36

{I.36

14 1.36

Protein.

8.418.35

9.9110.00

II .46

11.35

12.4012.36

9.999.96

10.1210.05

10.3110.31

Fat-4.864.90

4.22

4.24

5.015.02

4.614.62

4.414.42

4.804.85

5.245.26

Carbohy-drates.

85.6285.65

84.4684.34

82.0982.20

81.4581.46

84.2184.24

83.7183.74

83.°983.°7

1898. ]

Ash.

IS i 1.34I 1.33

16 J 1. 45I 1.44

I7JI.35J 1.34

18jI.48( 1.5°

19 J 1.413J 1. 4,3

!20 J I. 3F

J 1.331

2 I J I. 36J 1.37

22 J I. 3~I 1.34

23 J 1.4~i I.4Q

124 J I. 4~( 1.46

2511.6111 1.591

26 J I. 70I 1.70

27 J 1.43I 1.46

28J 1.55J 1.54

29 J 1.62( 1.62

30 J 1.63,I 1.621

31 J 1.451.i 1.48.

10.7910.67

13.8813.85

II .55II.52

II .63II .64

11.3011.19

II .81II .91

10.22

10.13

II.I4II.I6

II .46I 1.38

10.03ro.07

10.38ro.44

ro.95II.06

10.82

10.95

II .4511.54

11.49II .48

CHEMISTR+ Of' THE CORN KERNEL.

Protein.

9.709.65

II .88II .86

6.026.02

5. II5. IS

5.195.20

5.225.25

4.864.92

4.864.89

4.564.59

4.264.25

Fat.

4.014.01

Carbohy-drates.

84.9585.01

82.°582.10

Ash.

33.11.[6I 1.17

34 J 1.50I 1.52

3"i 1.45J I 1. 46

36J I.48i r .5°

37 J 1.58J 1.60

38 \ 1. 33( 1.36

39 J 1.62I 1.60

4°j r. 54i 1.55

4IJI.55J 1.57

42~I.47( 1.45

43J1.4Z( 1.48

44.1 r. 74I 1.73

45 1 1. 55J 1.54

46 J 1.60I 1.60

\ r .6047 '/1.58

48 i 1.38I 1.4°

49j I.42( 1.42

Protein.

9.019 13

12.3512.44

10.72ro.7I

ro.6910.67

12.9812.94

1 1.79II .81

11.91rl.88

ro.5310.46

11.061 1.13

II.8511.82

10.2110.26

8.368,43

r2.72r2.86

II .83II.73

12.°7

12.06

9.389.06

4.6g

4.71

9.859.95

4.954.99

--~-" ~

J~1;)

Fat.

'+.°44.06

Carbohy-drates.

85.7985.64

8r .548r.36

4.624.60

4.524.54

83.3483.45

78.9378.92

82.6982.76

4.924.90

3.983.95

4.804.79

4.554.54

5.5°5.52

4.384.39

4.934.98

5.475.54

4.874.94

4.244.26

4 934.93

4.604.62

8r.7981.88

81.8581.82

5.715.73

4.334.29

4.564.57

82.498:1,46

8j.I983-27

4.764.72

81,3'8r.24

4. IS4. r7

4.975.03

81.8781.72

4.864.82

84.4384.76

82.9782.98

82.3682.45

82;2782123

i

8Ih48I.i83

4.774.76

83.5083.47

82'.9782.85

83.6683.5r

82.8482.86

8r .5781.66

81. 9481.92

81.8081. 8 5

82.4282.48

82.g682.88

8r.6281.62

82.94-82.80

85.3585.21

32 i 1.381 11.78 484 82.00{

6i 1. 40 i II. 77 4: 82 82.01 50 I.65 12.28 4.76 8 r . 31

, 1. 5 12. 28 4.75 8 r . 32

IIt mu~t be adm.itted that th~se results are far from being uniform.

ndeed, ~hey are qUIte the opposite, and seem to bring out and clearlyto estab.h.sh the fact that there ~re extreme variations in the chemica.l

Co~posltl1n of cor.n grown fromlthe purest seed of a single variety andun er. martl edly UnIform field c01)lditions. Then the results given in the

expenmen~preceding this are toIbe cunsidered merely as averages froma large nu

!ber of small samples

lof widely vary ing composition.

1

82.6482.48

82.7°82.54

82,3682.25

,

82.18082.79

Ash. Protein. FatCarbohy.

Carboby-drates. Ash.16 (f) ) 1.58Protein. Fat. drates.II .78 5.09 81.55 24 (h) J 1.51Tip I I.S9 11.76 5. ro 8 I. 55 Butt I 1.49

10.49 4.01 1)3.99ro.46 4.00 84.0S

17 (f){I. 58 12.22 5. 13 81.07 25 (i)

J 1.47Middle. I. S7 12.26 10.58 4.58 83.37S.03 8i. 14 Tip I 1.48 10.61 4.60 83.3118 (f)

V.56 12.36 5.°4 81.°4 26 (i) .\ 1.45Butt '1.58 12.42 5.°3 89.97 Middle11.°5 4.56 82.96

\ 11.49I 1.44 II .°3 4.60 82.93

19 (g) II .99 4.86 81.66 27 (i) .I 1.47Tip / 11.49 II .97 4.84 81.70 11.°3 4.48 83.02Butt I T .48 10.96 4.46 83.1020 (g) J II. 51 12.49 4.77 8'.23 28 (j)Middle I 11.5 I 12 49 4.76 81.24 Tip {

1.77 10.87 4.36 83.00I 1.74 10.78 4.37 8.~.1I

21 (g){X. 5° 13.02 4.57 80.91 29 (j)

\ 1.65Butt 1.51 13.10 4.59 80.80 Middle ( 1.6211.35 4.56 82.44II.3I 4.58 82 4922 (h) \ 1.37 9.72 3.90 8S.0I

3°(j) \ 1.7 ITip /.35 9.67 3.93 85'.05 Butt (1. 72

II. 32 4.28 82,69, 11.28 4.29 82.71

23 (h) \ .37 ro.07 3.98 84i.58Middle I .35 10.08 3.97 84,.60

I

IS 2 BULLETIN NO. 53. [Jury,

Following are the maxima and minima of all constituents as shownby the

5° duplicate analyses:

Ash.Maximum 1.74Minimum. ...

"""""I .09

Protein.

13.88

8.35

Fat.6.023.95

Carbohydrates.

8;.79

78.92

Difference 0.65 2.07 6.875.53

With every constituent the variation is greater than Flechig foundwith 13 different varieties, and it is nearly as great as found by the Con-necticut Experiment Station with about 75 different varieties of corngrown under

9° presumably different conditions.This comparison is facilitated by the following table which gives

the number ot samples containing the different constituents in amountsabove and below certain specified percentagesj columns 1. and II. givethe numbers of such samples1 from my results and those of the Con-necticut Station, respectively:

AshProteinFatCarbohyrates

Per cent. I II.

above 1.70 I 5

13.75 1 36.00 ..I

85.00... 5 3

Percent. I. IIbelow 1.10 . . . . . . . . . I 9

9.00 2 44.00.. . . .. . .. I 2

79 .00. . . . . . . . . I 4

It is observed that the number of samples with percentages of ashoutside of these extremes is 2 with my results and 14 with the Connecti-cut experiments. This is in accord with the well known fact that theamount of ash constituents taken up by plants varies largely with theamount of soluble mineral matter in the soil, somewhat regardless ofthe needs of the plant; and it indicates wide variations in Connecticutsoils in this regard, as we should expect to be the case. By referenceto page 138 it is seen that the percentages of ash in the 90 samples variedfrom 0.91 to 2.10.

If we omit the ash, the number of percentages of all constituentswhich fall o1Jtside the limits given above is I I with my results from 5°samples and 16 with the Connecticut results from 9° samples.

ANALYSESOF PARTS OF THE EAR.-In studying this question 3° dupli-cate analyses were first made on different parts of ears. Five ears weredivided lengthwise into 3 samples each in the following manner: If theear were 12-rowed, 3 samples of 4 consecutive rows each were made;if I6-rowed, 3 samples of 5 consecutive rows each were made, onerow being left, etc., etc.

Duplicate analyses of IS samples thus prepared from 5 differentears gave the following results. The different ears are distinguished bythe letters (a), (b), (c), (d), and (e):

1Not single determinations.

--~-

1898. CHEMISTI1.Y OF THE CORN KERNEL.

iCarbohy-

Fat. 4rates.4.57 &3.224.58 83.24

'53

Ash. Protein.

I(a)JI.42 ro.79t 1.43 ro.75

2 (a)) 1.48 ro.97 4.54 83.0111.47 10.94 4.51 83.08

3 (a)) 1.50 10.66 4.53 83.3111.51 ro.72 4.55 83.22

4(b))I.SI 12.00 4.60 81.89II.S2 II.98 4.59 81.91

S (b) )1.49 12.01t 1.48 I2.0S

6(b)),1.48 12.19(,1.4712.08

,

7 (e) )il .37 10.09 5.24 8~,

' .30(11.37 10.10 5.17 8p.36

8 (c) )11.31 10.14 5.08 81.471,1.34 10.18 5.18 8.5.30

These results indicate'f . . . .

f'un,1 ormlty In the composItIOn of the different

parts 0: the ear. The fOllowing shows the greatest total't. .

the 6 s' I d t'. vana Ion III,Ing e e ~r~mations . of each constituent in anyone ear' and

also tht total vaflatlOn betwe!en the different ears:)

I IAsh. Protein. Fat. C bI~

,'any single ear. . . . . . . . . .

1

' .09 58ar ohydrates.

Inl five ears ..28.55

A+th.er lot.~~. ~~~. ~~'r's'~~:\elected2 ~I~d each ~/:hese \Va: ':~Vided

crosswISe mto 3 sam p les of' .I. . . approximate y equal amounts, which for

convenience are designated "tip," "middle" and "b".

lettered (f) ( ) (h) ( ' ), '. '

utt, the ears bemg, g, ,I , and (n.

The duplicate analyses follow:

Ash.

9 (e) ) 1. 36I r. 37

IO(d)) 1.39I 1.38

II (d)) 1.431 1.42

Carbohy-Protein. Fat. drates.10.15 5.20 83.29ro.20 5.17 83.26

10.46ro'46

4.284.29

83.8783.fi7

10.2510.27

4.224.20

8+.108+.n

84.3284.34

4.574.57

4.854.80

8,1.938.1.90

8[.488~.65

12 (d) .I 1.43I 1.45

13 (e) J 1.34I 1.36

82.6782.66

83.1383.21

10.0910.06

4.164. IS

4.804.78

I 1.19J 1.20

14 (e) J I. 30I 1.28

10.6610.62

4.914.89

IS (e)J 1.36I 1.36

10.8110.92

4.834.79

83.0082.93

Kernel, Ash, Ash, Kernel, Ash, Ash,weight. weight. per cent. weight. weight. per cen t.

I.... .0.3579 0.0048 1.34 6.....0.3953 0.0053 1.34

2.... .0.2947 0,0042 1.43 7.....0.4507 0.0066 1.46

3.... .0.3985 0.0052 1.30 8. . . . .0. 4589 0.0064 1.39

4.... .0.3585 0.0046 1.28 9.... .0.42II 0.0062 1.47

5.... .0.3936 0.0054 1.37 10.... .0.5072 0.0070 1.32

154 [Jury,BULLETIN NO. 53.

These results are similar to those in the preceding experiment.The following shows the total variation:

Ash.In any single ear. . . . . . . . .. .16In five ears. . .. .42

Protein.1.13

Fat.

.30

1.23

Carbohydrates.

1.06

4.253.43

It is observed that in every case the tip is lowest in protein and thatusually the middle is lower than the butt, the average total difference inthe ear being 0.73 per cent. and the widest I. 13 per cent. as shownabovel. The variation in ash and fat is small and shows no such pecu-

liarity. The carbohydrates, being estimated by difference, appear, ofcourse, as the complement to the sum of the other substances and showin the opposite direction approximately the variation of the mostvariable determinable constituent.

PARTIAL ANALYSESOF SINGLE KERNELs.-From 1009 separate deter-minations Richardson2 has found the average weight of 100 kernels ofair-dry corn to be 36.7 gms. Allowing 10 per cent. for moisture, gives

0.330 gms. as the average weight of the dry kernel. This weight is toosmall for a very exact single determination of a single constituent, and,of course, no attempt has been made to do more than that.

The ash determination was made by incinerating the whole kernelwithout grinding, the weight of the dry matter having been previouslytaken after drying the kernel for 8 hours in a current of hydrogen at1050; and the nitrogen determination was made on the whole kernelafter drying and without grinding, the digestion proceeding as satisfac-torily as with ground corn. No satisfactory method was found for thedetermination of the fat in a single kernel.

The ash determinations in 10 single kernels taken from as many. different places on an ear gave the following results:

For further work on the ash content several ears of corn wereselected, and from each a sample of corn, consisting of a number ofrows and believed to fairly represent the ear, was taken and its percent-age of ash in the dry matter determined. Then for the special investiga-tion of the ash conten t of single kernels four ears from the lot werechosen, of which two were high and two were low, comparatively, in the

lIt will be seen that later work on single kernels tends to confirm and establishthis as a characteristic of the ear of corn.

'D. S. Dept. of Agr., Div. of Chern. Bul. (1884)4, 82.

1898. ]I

CHEMISTRY OF THE CORN KERNEL.l

,..);)

iperceIj.tage of ash as previously determined. From each ear 10 kerne1swere sFlected at approxim~tely e.qual distances .apart throughout thelength iof the ear, the kerntls bemg numbered trom I to 10 and theorder ~unning from tip to bultt. The data from the ash determinationsin the isingle kernels and als~ the percentage of ash in the large samplefrom the same ear are given below:

Ear No. I.-Ash = 1.73 per cent.Kernel, Ash, A~h,weight. weight. per cent.

I .0.3334 0.0050 1.50

2 .0.3367 0.0053 1.57

3 .. ..0.3662 0.0059 1.61

4 0.3901 0.0061 1.56

5 0.3417 0.0057 1.676 .Q.3614 0.0061 1.69

7 9.3798 0.0065 1.71

8"'''9.4030 0.0066 1.649 d.4446 0.0073 ~.64

10""'1.4176 0.0071 1.74I .

Ear ~o. 3.-Ash = 1.10 perc~nt.

K~rnel. Ash, Ash,weight. weight. per cent.

1 0.2639 0.0029 1.10

2 .0,2591 0.0028 1.08

3.. .. .of 2655 0.0029 1.094 012887 0.0031 l.ro5. .. .. 0 j3077 0.0033 1.076 03216 0.0035 1:.097 .oj3363 0.0036 1,078 0-j3476 0.0038 I.ro9 0.13467 0.0042 1.21

10... ..0.4042 0.0045 I.II

Ear No. 2.-Ash = 1.65 per cent.Kernel, Ash, Ash,weight. weight. per cent.

r.. ...0.2933 0.0°48 1.642.. .. .0. 2797 0.0046 1.64

3 0.2945 0.0°48 1.63

4 0.2551 0.0°42 1.65

5 .0.3207 0.0°51 1.596... ..0.3005 0.0°49 1.637 0.3340 0.0°56 1.688. 0.3144 0.0°52 1.659. 0.3463 0.0°59 1.70

10... ..0.3627 0.0°58 1.60

Ear No. 4.-Ash = I. I I per cent.Kernel, Ash, Ash.weight. weight. per cent.

I. 0.3080 0.0035 1.14

2.. .. .0.3499 0.0043 1.23

3 0.3351 0.0°38 1.13

4 0.3422 0.°°40 t.175 .. .. .

°. 3970 0.0045 I . 13

6 0.3514 0.0°43 1.227... ..0.3767 0.0°47 1.258 0.4186 0.0°50 1.199 0.4331 0.0048 1.11

10 0.4638 0.0051 1.10

These results confirm those of the previous experiments in indicat-ing uniformity in the composition of the ear in all parts, although sligh t

variations are found, of course. It may be noted, however, that thevariation from the average percentage is rarely equivalent to more thanthree-tenths of a milligrammein the weight of the ash.

In the work on the protein content of single kernels,s ears,3 of

which w~re high and two relatively low, in protein were selected from anumber pf ears in a manner aIialogous to that described in the previousexperiment. i.

I

As duplicate determinatiob.s were not made with single kernels thecomplet~ analytical data of this work are reported.

Thel water used in making up reagents and standard hydrochloricacid andiin the analytical process where needed had been twice distilledonce wit~ sulfuric acid, to free it from ammonia, and once with caIciu~

156 BULLETIN NO. 53. [Jury,hydroxid to remove carbon dioxid and volatile acids. In standardizingthe hydrochloric acid and ammonia solutions the same automaticpipette and burette were employed as in the subsequent analysesl. The

hydrochloric acid was standardized by means of silver nitrate, a methodwhose details I have previously investigated2 and found to be exceed-ingly accurate. Lacmoid indicator was used in standardizing the am-

monia, and chemically pure cane sugar was employed in making

"blank" determinations to find the "correction" for reagents. Follow-ing are these data:

Standardizing hydrochloric acid.35 cc.' HCl gave 1.4103 and 1.4104 gms. AgCI.

Standardizing ammonia.17.5 cc. HCl required 27.55 and 27.55 cc. NH,.

Blank determinations with sugar.17.5 cc. of standard hydrochloric acid were taken and to neutralize the excess

of acid required

27.47. 27.45. and 27.47 cc. of standard ammonia solution.The atomic weights' used are: Cl = 35.453; Ag = 107.938; N = 14.041. The

factor, 6.25, was used to obtain the protein equivalent.

These data give 194933 as the logarithm (mantissa) for the weightof protein equivalent to one cubic centimeter of standard ammonia.

In the following work 17.5 cc. of standard hydrochloric acid were

taken in each determination, and the volume of standard ammonia re-

quired to neutralize the excess of acid is given' in the tables in cubic

centimeters:

Ear No. I.-Protein = 13.06 per cent.Kernel, Ammonia to Protein,weight. neutralize. per cent.

1 0.2945 25.12 12.46

2'"

.0. 3127 24.96 12.54

3 0.2893 25.16 12.44

4 0.2991 25.07 12.5°

5 0.3147 24.99 12.306

'".0.3162 24.94 12.49

7'"

.0.3544 24.63 12.508 0.3302 24.90 12.14

9 0.3601 24.67 12.1410... .0.3368 24.73 12.71

Ear No. 2.-Protein = 13.87 percent.Kernel. Ammonia to Protein.weight. neutralize. per cent.

1 0.3206 24.97 12.17

2 0.3207 24.81 12.94

3 0.3094 24.99 12.51

4 ...0.2841 24.97 13.42

5 ... .0.3475 24.55 13.126 0.2899 24.76 14.59

7,...0.2835 25.07 13.218.. ..0.3475 24.48 13.43

9 0.3179 24.79 13.1610...,0.3301 24.50 14.05

1If this precaution is observed, if the full measure of acid is always taken: andif the graduation of the automatic ammonia burette is strictly uniform. there IS nospecial necessity for the apparatus to read absolute values..

. .ZMethods of Standardizing Reagents.-Master of SCIence ThesIs. Cornell Um-versi ty, 1894.

'Twice the volume of the automatic pipette..Ostwald, Grundriss der allgemeinen Chemie (1890) 31.

1898.J: CHEMISTRY OF THE CORNKERNEL.

I~-J IEar No. 3.--Protein = 12,96 per cent.Kernel, Ammonia to Protein,eight. neutralize. per cent.

1 0.362624.79 1~.53

2""'f.3039 25.°7 112.32.3 .'1>.3353 24.85 1~.194 '1.3048 25.02 12.545.. "~.3225 24.96 12.146 .d.3013

24.97 12.957 ... .0.2635 25.30 12.848 .0.3204 Lost by accident.9.. ...0.3254 24.96 12.°410 .0.3195 24.86 12.75

Ear No. 4. --Protein= 7.59 per cen t.

Ke;nel. Ammonia to ProteinweIght. neutralize. per cent.

I .. ..0.25°3 26.277.452... .0.2432

26.29 7.543 0.2383 26.29 7.694 0.2II826',45 7.475. 0.2752 26.10 7.746 0.271925.95 8.70

7'"

.0.2758 25.97 8,468... ..0.27°3 25.96 8.699 .0.28°9 25.87 8.86

1°... ..0.3133 25.84 8.10

Kernel,weight.

1 0.2819

2. . . . .0,26823 .0.23784. . . . .

° .264 I5 .0)2891

Ear NO.5 --Protein = 8.40 per cent.Ammoni::,- to ProteinKernel, Ammonia toneutralIze. per cent.weight. neutralize.26.07 7.72 6 .0.3°02

25.7826.02 8.417 .0.2730 25.9126.19 8.37 8 0.2830 25.8326.06 8;.319 .0.2973 25.7625.98 8'.02 10 .0.2821 25.86

Proteinper cent.

8.768.89

9.02

8.96

8.89Th~ con.:ordant evidence of

3° duplicate analyses of parts ofears, of! 5° ash determinatiors, and of5° protein determinations insingle k~rnels would seem towarrant the conclusion and to establish

the fad that the composition of the ear is approximately uniform

throughci>ut.

Extrnded investig-ations, based upon the facts brought out in thesestudies cd the proximate composition of corn, are being continued bythe writ~r.

'

PAR[r Il.--THE COMP~ETE COMPOSITION OF CORN.

HISTORICAL.

THE ASH OF THE CORN KERNEL The earliest analysis on record of

the ash of corn is evidently that made by De Saussurel reported in

18°4.Following are his results:

Potash. . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . .. . . . . . . . . . , . . . . . . .. 14. 00Phosphate of potash . . . . . . . . . . .. . . . . . . .. . . ."

. . . .. 47.50Chlorid of potash. . . . . . . . ." " 0.25Sulfate of potash

... . 0.25Earthy phosphates. . . .. .. '. ',',"":""36.00

SrH~ ;:;d;:.: :..;.

H

; ;; ; : .;;1Rese?rches Chimiques sur la !Vegetation, by Theod. De Saussure (IS04) j51;

Trans. N. y. State Agr. Soc. (1848) 8, 727. .:

158BULLETIN NO, 53. [July,

Subsequently Letellier1 reported the following analysis:17.00

~i:::,e~~~: :":

" " ::::'. " '. '. :" " " " '. " " '. " '. '. '. '. '. :: '. '. " : " " '. " " '. :'. :" " '. " : ::

5: : ~:Phosphoric acid, . , , . . . . . . . . , , , , . . . . . , . . , , , , . . . . . . . . .

,

:::'. : '.: 0.80

~~:~:;i~' ~~id: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : '. '. '. '. '. ,. . . . ..

~:~~:Potash, soda, and loss., ,.. ",..." ,'

.,..,. ...",,

'. .' '11 show the analysis of Letelher gIvesAs the later InvestIgatIOns WI . ,.' h Much less. I the true composItIOn of corn as .very approXImate Y

f S r bur v of which he reported2 severalapproximate are the .analyses 0 a IS .

,

similar to the folloWIng:1.45 2.65

~~;h~Ph",./>::::::: ~:E )5

\4

~

9

5, 16.52

~;~::.~s.:~~ ~ ':

.:~

.: .:': ~ ~

.:~ ~ ~ ~ ~ ~

.:

.

.:~ ~

.'.'

"

..: '. '. ::::::

.::::: I

~:~~ + ~~NaCI .. .. .. . .. . .. .. . .. .. .. '

.. . .. .. .."

.. .. .. ... .°

,1°

~:i~'~.i~', ~~i.~~.:.",",.',".",:,:.:,:.:,",:,:,:.:,:.:.:.:.:.:.:.:.:.:.:.:,:.:.:.:,:.:.::

.~: ~~

;:;~

3 St fi Way and Ogston", andLater analyses by Liebig and

Kopp, ep,

Bibra" gave the following results:Liebig

and Kopp.

K20 3°.74N a2 0.. .

".

".., ..'"

MgO..., 14.72CaO " 3.06

FezO 0.84PzO, 44.50

S°., "'" 4.13

SiO z. .., ..",.. 1. 78

CI. ,..." 0.5°h ge of I s analyses of

In 1880 Wolff" gave the following as t e avera

the ash of corn:

1 Annalen der Chemie und Pharmacie (1844) 50, 4°3.zTrans. N. Y. State Agr. Soc. (1848) 8, 678.. I

b. ht liber die Fortschritte der Chem1e (1856) 8 5.. jahres ellc. .) 76 88

4 journal fiir prakh~c~e ~hem1e (lh5: .uf 'Agricultur (1865) I, 384.

'Liebig's die Chem1e In 1hre Anwen ung a

"Same reference.7And SO. and loss.

"And loss.Analyse n ( 1880 ) ; Thorp's Dictionary of Applied Chemistry

"Wolff's Aschen

(1890) 1, 497.

5 tepf.28.80

3.5°14.9°

6.321.517

Way andOgston.

28.371. 74

13.60

0.57

0.47

53.69Trace.

1.55

44.97

Bibra.

24.331.50

16.00

3,16

1. 88"

49.361.00

2.77

Bibra.

26.75

3.85

15.242.562.00tt

47.471,20

1.93

I898,jI

~zO.29.8

CHEMISTRY OF THE CORN KERNEL. 159

c.aO. Fe2O.. P2052.2 0.8 45.6

Na20.

I. I

MgO.

15.5

SO.o.S

SiO.2.1

CJ.

0.9

Q~ite recently Scovell and Peter have reported I a somewhat extend edinvestigation of the ash of cprn with reference to its content of fertil-izing el

f

' ments. Following are the percentages of potassium oxid andphosph ric oxid in the pure ash as found in 8 samples:

I .

"K,O. PoO,.1 K.,O. P.,OnI . I. .

"',28.38 48.52 , 29.66 52.14

',28.98 51.85 29.95 53.03

'29.41 52.45 29.27 53,1029.38 52.75 28.18 51.42

It seems evident that as a rule the ash of corn contains at least 95per cent. of the phosphates of potassium and magnesium, about twiceas much potash as magnesia being present.

THE PROTEIDS OF THE CORN KERNEL.-Zein, the most importantproteid in corn was discovered and named by Gorham in 18zI (seepage 130), although he concluded from his investigations that it was not

a nitrogenous body. The zein: was obtained by extracting with alcoholthe residue of powdered cor~ insoluble in water, 3,30 per cent. ofzein being found, By subsec/uent extraction of the corn with diluteacid and!1 alkali z, 75 per cent. 'pf what was thought to be albumen were

obtained i

Soo~ after the publication of Gorham's work Bizio" reported an innvestigatiqn of corn in which he. claimed to have discovered the alcoholsoluble pi-oteid, and, curiously enough, he states that he had named it

I .zein, from the Greek word meaning" nourishing substance" becauseof the fa!!,ct that it was a nitrogenous body. He points out severaldifference~ between his zein aI).d that which Gorham had found, andmentions lespecially tb at in 18~0 ConfigJiachi" had obtained am 111on iafrom zein', by dry distillation. ~y means of ether Bizio extracted oilfrom zein' and then found tha~ the residue was but partially solublein alcohol. These two port/pns, the one soluble and the otherinsoluble in alcohol, he thought to be two different substances andto be identical with the gliadin and zymom which Taddeii had foundin the gluten of wheat. He gives the alcoholic extract the followingcomposition:

Oi], soluble in ether. . , , , . , . , , , , . . . . . . . , . . . . . . , , . , , . , . .20.0 per cen t.Gliadin, soluble in alcohol.., , .43.4Zymom, insoluble in alcohol. ., .. . , . .',. . . , . . . . . , .36.6

~

'Kentucky Agr, Exp. Station Report (1891) 16.2journal fur Chemie und Physik (1823) 37, 377.

"Ibid. (1823) 37, 383..

<Ibid. (~820) 29, 514.

160 [Jury, 1611898.,

\

] CHEMIS'rRY OF THE CORN KERNEL.

i1iJltimate organic an~lyses of these four preparations gave the

folloting results:I

BULLETIN NO. 53.

Salisbury! obtained" albumen" from corn by extracting with

water and coagulating by heat, and" casein" from the filtrate byprecipitating with acetic acid. He extracted zein and oil by means of

alcohol and separated them by evaporating the alcohol and extractingthe oil with ether.

Evidently because Berzelius2 in commenting on Gorham's results,

had expressed the opinion that the ze!n of corn and the gluten of wheatwere identical, Stepf3 assumed and stated incorrectry that Gorhamclaimed to have obtained zein by kneading corn meal with water, in thesame manner as gluten may be obtained from wheat; and he triedrepeatedly but in vain to accomplish such result. By extracting corn

with alcohol and purifying the extract by treating it with water and withether to remove sugar and oil, he states that he obtained pure zein verysimilar to that obtained by Gorham. It was easily soluble in alcohol,but by repeated solution and evaporation of the alcohol the zein waspartially changed into a modification insoluble in alcohol. Stepf called

the two modifications plant glue (Pflanzen/eim) and plant casein, sub-stances already known.

Albumen was also obtained from an aqueous extract of corn bycoagulating -with heat. The dry matter of corn was found to contain-

0.7 per cent. of albumen and 7.5 per cent. of zein. Stepf further ~tatesthat from four closely agreeing determinations he found pure zem tocontain 15.6 per cent. of nitrogen.

In 1869 Ritthausen reported" an investigation of the proteids of thecorn kernel. Misled by Stepf's erroneous assumption, Ritthausenvainly endeavored to obtain a cohering glutenous mass by kneadingcorn meal with water.

Zein was obtained to the amount of 5 per cent. by extracting

powdered corn with alcohol and (A) by evaporating the alcohol andextracting the residue with ether, or (B) by precipitating the zein in thealcoholic extract by the addition of much ether. Zein was further puri-fied (C) by repeated treatment with alcohol and. ether, .and (D) .b!, ~is-

solving in 0.1 to 0.15 per cent. potassium hydroxld solutIOn, preclpltatmgwith dilute acetic acid, redissolving completely" in alcohol, andprecipitating with much water.

A. B. C. D. Average.Carbon... . . . . . . . . . . . . 54.66 54.7I 54.76 54.66 54.69Hydrogen. ..

".. .. . .. 7.45 7.50 7.57 7.5 I 7.5 I

Nitrog~n 15.50 15.53 r5.45 15.85 IS.58

SUlfuri " t 0.69 0.65 0.69'

Oxygei""""""'" f 21.7~ 22.162 22.22 21.33 21.53

T~e fact may be noted fhat these results were not corrected for theash content of the zein, whiCJ:hit is st:lted was insignificant; and also themore ilimportant fact that the nitrogen determinations of both Stepf andRitthausen were made by the method of Varrentrap and WilF employingthe old atomic weights of pl~tinum (197.2) and nitrogen (14). I haverecalculated their results using the revised atomic weights (Pt= 194.8;N=14.041)4 and find Stepf's average of four determinations to be 15.84per cent. nitrogen and the average of Ritthausen's results" to be 15.82per cent. nitrogen, in zein, while preparation (D) alone gives 16.10 percent. nitrogen.

By repeated solution in alcohol and evaporation of the solvent,

Ritthausen obtained zein wrich was insoluble in alcohol" dilute orstrong,.warm or cold." He ~tates positively that zein (or Maisjibrin,ashe prefers to call it) is not ~ mixture of proteid bodies but a single

homogtneous substance. ,Af~er the alcoholic extra(::tion of the corn was complete, the residue

was exttacted with 0.25 per cent. potassium hydroxid solution, and theextracted proteids precipitated by acetic acid. About 0.5 per cent. ofsubstant;:e was thus obtained from corn, which Ritthausen has sincereferred~ to as globulin. He gives the following as the composition ofthe ash-'free substance: '.

iCatbon

""""""5 1 . 4 r

~ itfr;:::~ :: : : : : : : : : : : :

.: . :

!I: : : : : : : : : : : : : : :

:.: : : : : : : : : . : : : :

.: : r; : ;~

Oxygen and Sulfur : 23.68

--'Sulfur determination in (D) was not considered trustworthy.

2Should be 22.26 evidently.

3Annalen der Chemie und Pharmacie (1841) 39. 257.

'Ostwald, Grundriss der allgemeinen Chemie (1890) 3I.51 have checked this recalculation from the weight of zein employed and ()f

platinum found as reported in Ritthausen's analytical data, and find that he usedatomic weights as stated above.

RLandwirtschaftIiche Versuchs-Stationen (1896) 47. 391.

'Trans. N. Y. State Agr. Soc. (r848) 8. 727.2Jahresbericht tiber die Fortschritte der physischen Wissenschaften (r823)

2. 124.3Journal ftir praktische Chemie (1859) 76, 88.

4Journal fiir praktische Chemie (1869) 106, 47I.

5Ritthausen points out that this action shows zein to not consist in part of casein.which would have formed an

,.alkali albuminate" insolu1;>lein alcohol.

162 BULLETIN NO. 53 [Jury, 1898.J CHEMISTRY OF THE CORN KERNEL.

In 1877 WeyP pointed out that a 10 perchlorid extracted from the powdered cornwhich coagulates at 75°.

The corn proteids soluble in sodium chlorid solution have beenvery thoroughly investigated by Chittenden and Osborne2 and the pre-

vious work on zein, the alcohol-soluble proteid, was carefully repeated.With 10 per cent. sodium chlorid solution they extracted from

powdered corn about 0.5 per cent. of proteid matter from which theywere able to separate at least four different bodies now known3 as (1)proteose, (2) very soluble globulin, (3) maysin (globulin), and (4) edestin(globulin). As the salt is removed from the solution by dialysis, themaysin and edestin precipitate, the other bodies remaining in solution.By long continued dialysis a part of the very soluble globulin is pre-cipitated, the remainder (originally thought to be albumen by Chitten-den and Osborne) being precipitated by hydrochloric acid. Of theproteose, a part (also first called albumen) was obtained by coagulating

with heat, and the remainder was precipitated with alcohol. After re-diss0lving in salt solution the mixture of the two precipitated globulins,maysin was separated from edestin by coagulating with heat, theedestin being finally precipitated as the salt was removed by dialysis.Other methods 'were also employed to separate these two globulins,based upon the fact that maysin is readily soluble in extremely dilutesalt solutions, while edestin requires greater concentration of salt forsolution.

The averages of all analyses of each of these four proteids follow:

Very solubleglobulin.52.846.8215.381.3723.59

cent. solution of sodiumkernel a globulin proteid

163F II '

. :0 i {lllg are the maxima and' .

determined in all an a-lyse f '

mllllma of the several constituents

"

s 0 proteose ver y I bl I .insolublejmodification: '

so u e g obulm, and the

PVery soluble

Insolubl eroteose. globulin.Carbon 6

modification.,''''''

52.0 t050.07 53.53 to 52.36H.ydtogen 6.91" 6. 54

53.95t051.97

N 6.90"6.74 7 " 61tr6gen ... 17 . 28"

15 . 78.05 . <)0

S I '5.69,.

'5.,6 6 Su f~r.. .. . .. . ..'"

2.37" 1.62 1. 4 8

"1 2 6

I.. 2 "15.87

I. I. r6 r,

I. 12The ~everal analys f bh .

row limits'es 0 ot mayslll and edestin agree within nar-. ,

After! the extraction with Isalt s I .most abu~dant proteid in th ' -k

0 utlOn was completed, zein, the

with 75 pdr cent. alcohol at :b~t:n ~rnel, w~s obtained by extracting

solution in alcohol and r"

.50, ~nd hIghly purified by repeated

being removed b fi IP eCIP.ltatlO~ wIth water, the last traces of oil

y na extractIOn with ether.By ~arming with water or very dilute alcohol

changed llltO the insoluble modificatioll. zein was readily

sever~~~lowingis th~ composition of zein as shown by the avera es of

mOdi1lcat~~~~~agreemg analyses of both the soluble and the ins~luble

Proteose.Carbon. . . . . .51.30Hydrogen. . 6.71Nitrogen... .16.35Sulfur ,. 2.00Oxygen.. . . . .23.64

Maysin.52.687.0216.781.3022.22

Edestin.51.716.85

18.12

0'86

22.46

Carbo',Soluble zein. Insoluble zein.

H d

I;t 55.28y rogen : 55.15

Nitrog~n """",""""""" 7.27 7.24

Sulfuri... ...

" 16.09 16.22'."'" """ """"Oxygen.... . .. .. .. . . .. .. .. .. . ... 0.59 0 62

I. . . . . . . . . . .

~. . . . . . . . . . . . .20.77 20.77The statement is made that "corn I

with salt sojution and warm dilute alco~~~a, .a~~er I~h~rough ~xtractionto dilute solutions of potassium hydroxid ('

Yle s Itt e proteId matter

0 b' .'.0.2 per cent.)."

t bs ornF s more recent mvest1gation'sl have shown this assumption

0 every 9rroneous; and he now estimates such treatment to i

;~:~ti;:rce

I~tt.. ,of proteid soluble I,in 0.2 per cent. potassium hYd;o:~~

. ,IS noteworthy that this t't.am t f b .:

quan I y IS seven times the totaloun .0 t, e several protelds extracted by salt-solution A I

the punfied preparation gave the following results: . na yses of

Carbon. . . . . . . . . . . . . . . . .

H d ""'" 0""'" ""'0'""

6,y rogen"""

. . . . . . . . . . 5 I . 2

J::::;:::.~::::::::~::::::~:.::~:~.:~~:~~~~~~~~::::~:~~:~:~::::';:'::--~ .25.30

1Conn. Agr. Exp. Station Report (1896) 20, 391.

The different preparations of proteose and of the very solubleglobulin show some wide differences in composition which, it is believed,are "simply due to their alteration by the process made use of" in theirseparation. It was found "that these 'soluble bodies are exceedinglyprone to change." By the long continued action of water and saltsolutions an insoluble modification of variable composition was pro-duced from maysin and the very soluble globulin.

--lZeitschrift fur physiologische Chemie (1877) I, 84.

2American Chemical Journal (1891) 13,453, 529; (1892) 14, 20.

'Osborne, Conn. Agr. Exp. Station Report (1896) 20, 391. To avoid confusionthese terms are here used instead of myosin, vitellin. etc.

164 BULLETIN NO. 53. [Jury,

The quantities of the different proteids in the corn kernel are esti-mated a's follows:

1. Proteose. soluble in pure water ,.",..."..", ,0,06 per cent.2, Very soluble globulin "..,.,.."",.,..., O,04 ..

3, Maysin. soluble in extremely dilute salt-solutions",. ,0.25

4. Edestin, soluble in more concentrated salt-solutions., ,0,10 ..5, Zein. soluble in alcohol, . . . . , . . , , , . . . . , , . . . . . . . , , . .5,00

.,

6. Proteid matter, soluble in dilute alkalies""",..", .3.15 ..7. Proteid matter 1 insoluble in any of these solvents, . ,,1.03 ..

Osborne has calculated the mean percentage of nitrogen in cornproteids to be 16,057,

In a review of the percentages of nitrogen in the proteids of variousvegetable substances, Ritthausen2 places corn in the class with proteidscontaining 16.67 per cent. of nitrogen, and uses the factor 6,00 for cal-culating protein from the percentage of total nitrogen, It is observed,however, that Ritthausen has misquoted his own results on the composi-ti'on of zein, as will be seen fr.om the following:

Original3,

Carbon. . . , , . .' """"'",.., "",.,,54.69

Hydrogen. , , , , . . , . , ... . , . , , . , , , , . , . , , , ."

7. 5 INitrogen'. , . , .. .,

""""""""""'"15

'58

Sulfur, . . . . . . , , . . . , , , . . . . , , , , . ,'

, . . , , . , ,. 0.69

Oxygen, ",."". ". .,..'"""""

,21,53

As quoted.

54,69

7,56

16.330,69

21,53

An error of 0,05 appears in the hydrogen and of 0.75 in the ni tro-gen, and furthermore the total is 100,80, clearly showing that theanalysis is misquoted. His analysis of globulin is quoted correctly,

In this connection it is interesting to note that, if we take Ritt-hausen's determinations of zein (containing J 5. 58 per cent, of nitrogen)as 5.00 per cent. of the corn, and globulin (containing 17,72 per cent,of nitrogen) as 0,50 per cent. of the corn, and recalculate the nitrogenaccording to the revised atomic weights of platinum and nitrogen,which show zein to contain 15,82 per cent. and globulin 17,99 per cent.of nitrogen, we then find the mean percentage of nitrogen in the pro-teids to be 16.02, which is practically identical with Osborne's result,and proves conclusively that with our present knowledge we are to use6,25 as' the factor for estimating protein from the total nitrogen contentof corn, '

THE CARBOHYDRATESOF CORN,-Gorham and Bizio, to whose workreference has already been made, separated sugar, gum, fiber, 'and---

INitrogen in residue from 100 parts of corn multiplied by the factor 6.25.2Landwirtschaftliche Versuchs-Stationen (1896) 47. 391.3Journal fur praktische Chemie (1869) 106. 483.

1898.]CHEMISTRY OF THE CORN KERNEL.

st~rch in the carbOhydrate group,h h

beIng es~imated by difference:wit t e following results, the starch

!Ca~bohYdrates.Sugar '

Gorham.

G I '"'' .. , .. .. .. .. . .. .. .. ..I 59Ulp, .. , . . . . . . , , , . , , .

".' ,','

"

. . 0,90

Fiber. , . , . . , , ,

. , , . , , ., 1,922 2

Stafch': : : :-::": : :

.. .. . .. ... ..,3.30 7:7~, , , , , , , , , ,

','

, . . , , , . , . . . , . . , ,84,6080.91

In connection with his researches u onvegetable substances includin g K

p the starch content of manyI corn, rocker1 showed th bappreciable amounts of sugar 0

',' r d t '

, e a sence ofM '

I ex rme m the ri p e d fltscher1ich is q uoted h"

see s 0 cereals.1

as avmg reached theKrocker'~ method for dete

" h '

same conclusion.

~

rml mg starch was by h d I .mentatio , the amount of star'

,

h b '

Y ro YSls and fer-

carbon d oxid liberated Ic

deIng calculated from the weight of

. n mo ern chemistr y th I .pressed qy the fall' I" e re atlons are ex-

, OWIng equatIOns, In which thwater and is converted int I e starch first takes up

acids:0 g ucose-sugar by the catalytic action of

l65

Bizio.

C6H,005+H2O=C.H1206and then the sugar is decomposed into alcohol

yeast, and carbon dioxid by

C.H120.=2C2H5OH+2C02,In case a measurable quantity of hexose

determined by fermentatio'-sugars were present it was

Duplipate determinati:~r::l~~::p~:eo~l~~~:IYSiS o~ t,he starch,cen t. of wtter gave the following results:

contamIng 14, 96 per

~:;=o~~~:x;d'i~~~d':::::::::::::::::3,35 2,98 gms.

Starcl1 equivalent 1.02 0.92Starch in dry matt~~', : " : : " "" '. "

: " " '. '. '." "1.877 1,693

65.88 66,80 per cent.

, Aside from the determination ,of fiber as comm proximate analyses and Atw

at ', , .monly made and reported

.'er s estImatIOn of sug (nothIng furt

,her of im p ort "

ar see page 134), ance concernr ng the chem' I 'the carbohydrates of corn is fourld t'I Ica composition of

foHowing p~rcentages of differend ca~:~h 1~87, w~en Archbold2 gives the

"the average of man y sam p le sI

I d

y :ates In corn, as representing. ! ,ana yze In the cou f

workIng" ir a large starch factory: rse 0 one year's

Water ".,.,.Starch '

, . . . , . . . , . . , . . , , . , , , , . , , , , . ,

"" "'".........

Cellulose, , . , ,

---Gum and sugar: : : : : : : : : : : : : : : : : : : : ~. : : . : : : : : : :

I Annalen der Ch .d. emle un Pharmacie (1846) 58

'Journal Society Chemical Industry (1887) 6. 8~ 212.

I 1.20

54.80

16'40

2.90

Dry

61,71

18,47

3.27

166 BULLETIN NO. 53. [Ju~y,

Arch bold's report shows' that 55.6 per cent. of starch are actuallya btained from corn (dry basis) in the commercial process of starchmanufacture, and that several different by-products still contain tr'lcesof starch.

In 1889 Washburn. reported an investigation of the cane sugar con-tent of corn. By extracting 1400 gms. of ordinary field corn, to which

3 gms. of magnesia had been added to prevent possible inversion ofsugar, with 72 p~r cent. alcohol, shaking the solution with ether toseparate fat, and purifying the sucrose in the filtered aqueous layer byrepeated precipitation as strontium sucrate and decomposition of thepreci'pitate by carbon dioxid (method of Schultze3), 1.105 gms. of purecane sugar were obtained by crystallization. American sweet cornyielded larger amounts, 10.5 gms. of sugar being obtained from 2000gms. of corn. Washburn states that all of the sugar in the corn is not

. obtained by this process.

Marcacci' has found over I per cent. of sugar in corn.Pentosans (Cr,HsO,), which are also termed wood gum and hemi-

cellulose, were found in corn by Stone5. These carbohydrate bodiessyield pentoses (C5HlOO5), also called penta-glucoses, by hydrolysis withdilute acids (Cr,HsO,+H20=C5HlOO5)' and furfural (C5H.o2) by dis-

.

tillation with moderately concentrated acids (C5H1OOo-3H2O=C5H,O.),reactions which serve as a basis for their quantitative determination.Either the pentose is determined by Fehling's method7 for reducing--

'Based upon six years' experience as chemist to a starch factory.2Uber den Rohrzucker des Maiskorns, etc ,- Inaugural Dissertation zur

Erlangung der Doctorwiirde,-Gottingen (1889); Journal fiir Landwirtschaft (1889)37, 503.

"Landwirtschaftliche Versuchs-Stationen (1887) 34, 403.4Le Stazioni Speriment, Agrar. Ital. (1889) 17, 266; Central-Blatt fur Agri-

cultur-Chemie (1890) 19, 352.

"American Chemical Journal (1891) 13, 73.GTwo pentosans are well known: Xylan, found quite commonly in grains and

grasses; and araban, occurring especially in gums such as arabic, tragacanth, cherry,etc. Xylan and araban have the same empirical molecular formula, but theymay be distinguished by the difference in the specific rotation and melting points ofthe respective pentoses, xylose and arabinose, into which they are converted byhydrolysis. For xylose [a]D=18° to 19° and M. P.=144° to 145°; while forarabinose [a]D =I<?.3° to 105° and M. P.=154° to 157°. Cf. Koch, PharmaceutischeZeitschrift fur Russland (1886) 25, 619 and other pages; Berichte der deutschenchemischen Gesellschaft (1887) 20, III, 145: Bauer, Landwirtschaftlicbe Versuchs.Stationen (1889) 36, 304; Stone and Tollens, Annalen der Chemie (1888) 249, 227;Wheeler and Tollens, ibid. (,889) 254, 304; Schulze, Zeitschrift fur physiologischeChemie (1890) 14,227; (1892) 16, 387; (1894) 19,38.

7Bauer, Landwirtschaftliche Versuchs-Stationen (1889) 36, 304: Stone, Ameri-can Chemical Journal (1891) 13,78.

1898,1 CHEMISTRY OF THE CORNKERNEL.

1117sugars; or the furfurol is determined, preferabl

'"phenyl ~ydrazine as a hydrazone ( CH ON HY bf precIpItatIOn with

St f d "'9 C6H5). one Oun corn bran to contain 1 2 -

1'0.

sans. 2 ~chulze,:J after separatingconsid~r;ble ;~:

7 per cent. of pen to.

bran, obtained a residue which yielded ~er matter from COrn

which h~ showed to be xylan.'.

:

43..) 7 per cent. of a pentosan

In ~896 StoneD reported al somewhat extendedhydrates: of corn in which'

d .study of the carbo-

I 'sucrose, extnne starch

fiber wet.e determined quantitativel y T l '

, pentosans, andb b'

. .. Ie general method1 dmay e. ne-fly described as follows: emp oye

SUcf'ose.-Finel y g r dI . oun sorn meal was extracted withal.cohol ~hIch was then evaporated near! to dr. . 95 per ceot.WJth wat~r, treated with hydro hi' ~

dyness, the residue taken IIp

i C onc aCI the invertedby Fehling's solution and calcul

t d t ' sugar estimatedI . I a e a sucrose.

Dexvirme. -The residue or meal was extracted'

was then jevaporated to a small' v I h d .wIth cold water which

LI a ume, t e extnne b . . .by alcohfl, inverted by hydrodhl'

'd.

.emg precIpitated

solution. I I onc aCI , and estimated byFehling's

.Starch.-A known proportion of the residue of

wIth malt extract the solutionh d I d

meal was treated. '

y ro yse and theb .estImated by Fehlin g 's soluti d 1 I

,sugar a tamed

'.

on, an ca cu ated to starchPentosans.- The residue from the star' .:

with 1 per cent. hydrochloric acid th ch determmatIon was boiled

Fehling's solution and calcu lat ' d t ' Ie pentose formed estimated by

. e 0 XY an..

Fiber. -The residue still remaining was boiled withsodIUm hydroxid, and the insOlu

, ble matter ( Ie h) '

1. 25 per cent.

A .I f

ss as gIVen as fibersaf:\lp e 0 corn which contained 80 6 . . .

hydrates, ~hen estimated" b 'difference'" 9 per cent. of total carbo-

the following results:y , gave by the above method

Sucrdse . . .Dext~ine

. . , . ." . . ..

'".

"".

'"0.27 per cent

Starch . ~: : : : : : : : : .' .' : : : :.. . ..

'" """ 0.32"

.

Pentdsans. . . . , . . . . . . . , . . . . . . . . . . . . . . .42 .50

"

Fiber'. . . . : : : : : : : : : : : : : : : : : : : :: : : .' : : : : : : : : : .

: : : : : : : :: ;:;~

Total carbohydrates.. ---- i ,

"""""" 50?'?"'Flint rnd Tollens, Landwirtschaftliche Versu h .

.--Berichte derldeutschen chemischen G~sellschaf (8c s-StatlOnen (1893) 42, 381. Cf.

2912.: It I 91) 24, II, 3575; (1892) 25, II,

2The r

tSUlts were pnblished (Amdrican Chemical

of furfurami" but are here calculated C tJournal (1891) 13,73) in terms

3' ... 1'0 pen osan.Zeltsc~ rIft fur physiologische C~emie (1894) 19

4The statement by Stone (V. s. De t of A r ,41..

that Tollens and Flint (Berichte der d t h ~ ., ~xp. StatIOn Bu!. (1896) 34, 16)

2916) had estimated the amount of 9u tSC en c. emlschen Gesellschaft (1892) 25, II,pen osans In COrn bran to b

8appears to be erroneous as the work referd t

e 3 17 per cen t.5U ' re 0 was with corn cob (llf. .

k. S. Dept. of Agr., Exp. Station Bul.. (1896) 34. s azs.olbe1l).

168 BULLETIN NO. 53. [.fury,

In discussing his results, Dr. Stone says:

" This method not only permits the separation of the more delicate and easilydecomposed carbohydrates from those which offer greater resistance to. reagents, butfrom the very beginning of the process any carbohydrate not wholly removed at ::onyparticular step would hardly fail of being detected at the next succeeding and moresearching reaction. It is considered pertinent to the subject under discussion to callattention to the apparent discrepancy between less than 50 per cent. of carbohydratesfound in our most prominent cereal grains by direct and fairly accurate methods ofdetermination and the 70 to 80 per cent. commonly ascribed to them by the indirectmethod of estimating' by difference.' From 20 to 30 per cent. of the grain or flouris not accounted for. Under the conditions this matter cannot be conceived of aspossessing a similar nature to the sugars, starches, or even the more easily solubleforms of gum or celluloses. "

When weremember that Krocker had shown (see page 165) by a directand positive method that corn contains over 65 per cent. of ferment-abiel carbohydrates (at least almost entirely starch), and that Archbold,from long experience in the manufacture of corn-starch, reports over60 per cent. of starch present in corn and at least 55 per cent. actually

recovered in the commercial process (see page 166), the previously exist-ing evidence of an error in Stone's results is apparent. Dr. Stone hassubsequently discovered and reported2 a large error in the starch de-termination, due to the use of too dilute hydrochloric acid andconsequent imperfect hydrolysis. The percentage of starch is nowgiven as 65.45 instead of 42.50 as first reported. The total carbo-hydrates thus found by determination become 73. I7 per cent. ascompared with 80.69 per cent. estimated by difference, Dr. Stoneconcludes that:

"This discrepancy may arise from one of two sources, .viz.: I. Error in thedetermination of the carbohydrates. 2. The existence of a substance which is freeof nitrogen and is of a character not usually ascribed to carbohydrates and resistantto the ordinary reactions for such. While the first alternative is not excluded, thewriter is inclined to the latter conclusion and expects to continue the investigationalong this line."

In a recent report of extended investigations of methods for the

estimation of starch, Wiley and Krug3 refer to their experiments with

the conversion of starch into maltose and dextrine by the use of malt

extract, as follows:

"The residues from the diastase digestion were all thoroughly washed with hot

water and then examined with iodine under the microscope. In every case a large

number of cells was found which contained undigested starch, showing that the

sample' had not been ground to a sufficient degree of fineness. This is, therefore,

--IThe pentosans are classed as strictly non-fermentable carbohydrates. Cf.

Koch, Pharmaceutische Zeitschrift fiir Russland (r886) 25; Stone and Tollens,Annalen der Chemie (r888) 249,257; Stone, American Chemical Journal (r89r) 13,82.

0 Journal American ChemIcal Society (1897) 19, r83, 347,3Ibid. (r898) 20, 2554A sample of wheat previously analyzed by Stone.

1898. ] CHEMISTRY OF THE CORN KERNEL.169

another source of error in Professor Stone's w kand the starch determined

Th '

or. The sample was then reground. . .

"e resIdues were ag

, .d .

Case found free from starch showing that th'

ham exam me and 10 every

Th 'e conversIOn ad been complete

. e number for starch thus obtained added to . . . .

stituents gives us a total of 99.28." ' our per cents. of the other con-

, !n summarizing their results Wiley and KrugOpInIOn:

express the following

of a c~J~~ s:r~:eqUa;tity of matter unaccounted for in the cereal grains is doubtless

whose cti,em~cal an~au:e, ,be

llonging t~ that complex class, pentosan-ligno-celluloses.

'j I' YSlca properhes are so nearl y ark kseparation and deter' t. . I e as to ma e their exact

fmma IOn extremely difficult Th

t" fmined b dies in cereal gra'

."

. e quan Ity 0 these undeter-111SIS very mlDute."

cove~jEOIL .0: ;?RN.-ThJ presence of oil in the corn kernel was dis-

h f IIIb.y B1ZIO In 1823. A partial analysis by Hoppe'Seyler2 gave

t e 0 PWIng as the percentage composition:J of the oil:

C~olesterol.",...".. .. .. j,Pr1otogon.. . . . . . . . . . . . . . !. . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . 2.65

Saponifiable fats etc, .. .. ::r, '.:.. .. , ., ., ,', ,.,

3 . 95

! 1 '".

""'" """"'", ".,.

". 93.4°Th

j!: ~tatement is ma~e t~at the oil contains stearin, palmitin, and

much o,em, and the meltmg J!>oint of the fatty acids is0"

D

54° F, [11°] to 120 c.]. ! blven as 51 to

h

Some of the .so called physical and chemical" constants," whichave been determmed by several investigators are given below:

Specific g;avity UnsaponifiabJe Iodinof 0~1. substance. absorption.

Spiiller' .."'"''

, :~t15 C.) (per cent.) (per cent.)

Smith".. .. .. , .. ..""'"

1. 35 II9,7

Hart 6.. , .. . .. ..""

..0 . 9244 I 22. 9

Rokitianski7 ,.. ..',:""""0.9239 1.55 II7.00.8360 75.8

The oil used b y S!Jull r h d '; e was t e or mary ether extract. Roki tian ski

used a petroleum ether extract. Hart worked with a "dark brown"sample ~resumably found on the market. Smith's material was obtainedon the lI1arket, but was of a "bright golden I

" da fair sainple of corn oil.co or an was probably

:Jour~~l ~ur Chemie und Physik (r823) 37, 377.

depar~edlclDlsche-Chemische Unt~rsu~~ungen, 1, r62; Bulletin Societe Chimi ue

31 h(j866) [2] 6,342, Jahresber,cht uber die Fortschritte der Chernie (1866) 2-8

lve not been able to see Hop S I' " '-'".

protogon i~ the substance now termed ~:~it~neras :r:~lDal paper. Presumably tbe

matin~ it ~nd ch~lesterol were simihtr to those ~hi:h ar: d::~~~~~ ~:~::yedin esti-

5

PolJrtechDls~hes Journal (Dingler) (1887) 264, 626. .

Jou~nal SocIety Chemical Ind6stry (r892) II 50

~Ibid!. (1894) 13,257, from Chtm. Zeit. 17, I~22.4'Inaugural Dissertation St. Petersbur ( 8 ) . Ph .

Russland (18 ) 33 . ~ '. '

g r 94 , armaceutJsche Zeitschrift fiit:'94 , 712. Chemlsches Central-Blatt (r895) [4] 7, I, 22.

170 BULLETIN NO. 53. [Jury,

Spiiller observed that the oil absorbed no oxygen from the aIreven after fourteen days' exposure. Smith states that the freezing pointof the oil is below -20°. Hart gives the melting point of the fattyacids as 25°. Rokitianski reports further qualitative chemical workwhich showed the oil to contain oleic and linolic acids. It is evidentfrom the specific gravity and the iodin absorption that the material withwhich he worked was not ordinary corn oil.

Willey and Bigelowl have recently found the heat of combustion ofoil of corn to be 9280 calories per gramme.

EXPERIMENT AL.

In a preliminary study a small amount of oil was obtained bycollecting the ether extract from a large number of proximate analysesof corn. In this, advantage was taken of the fact that the oil is moder-ately soluble in alcohol when hot and but slightly so at ordinary temper-atures.2

The oil was transferred from the small flasks, used in its extraction,by means of hot alcohol to a single vessel. On cooling the oil precipi-

tated and settled to the bottom, the alcohol being each time decantedfrom the collected oil and used in transferring the next lot. Finallythe alcohol was evaporated and the oil dried to constant weight in awater -oven. When freshly obtained from white dent corn the oil isnearly colorless, but on standing a pale yellow and finally a deep golden

color develops, plainly indicating a gradual change in its condition,presumably due to absorption of oxygen. This was confirmed by deter-m'ining the iodin absorption which was found to be 115.5 percent.

A large quantity of corn oil, including samples from four differentsources3, was then secured in order to make a more thorough investiga-tion. The oil is obtained as a by-product in the manufacture of corn-starch and glucose-sugar, and all of the samples secured were of a palestraw color and evidently fresh and pure.

Specijic Gravity. -Three of these samples of corn oil were sufficientin quantity to enable me to make determinations of their specific gravityby means of a delicate Westphal balance which by trial gave the specificgravity of pure water at IS° as 1.0000. The samples of oil gave thefollowing results:

2.

°'9262

3.

°'9258

t.Specific gravity.. .. (IS') 0.9245

-------1 Journal American Chemical Society (1898) 20, 3092Smith has found the solubility of corn oil in alcohol by volume to be 2 per

cent. at 16° and 13 per cent. at 63°,"SampJes of corn oil were very kindly furnished me by President Wm. F, Piel,

Jr" of The National Starch Manufacturing Company. New York City; by The Chas.Pope Glucose Company, Geneva, Ill.; by The Glucose Sugar Refining Company,Chicago; and by Messrs. Elbert and Gardner, New York City.

1898.J CHEMISTRY OF THE CORN KERNEL.171

Melting POint.-Preliminary experiments confirmed the observationof S~ith th.at the oil is still fluid at -20u, a temperature of -z3(

(obta.med wIth snow and concentrated sulfuric acid) failing to solidifythe at!. It was found, however, that the oil became hard and solid atabout -36°.

Th~ melting point was determined by a modification of the methodof the 1ssociation of Official

iAgricultural Chemistsl.

I~ ~ tall beaker of abo~t 2.5 liters capacity was placed a smaJlquantIty, of concentrated sulf/Hic acid (to absorb water vapor so thatthe app~ratus would ~emain tra~sparent at low temperatures). A secondbeaker ?f about 2 lrters capa

.

CIty was placed in the first beino' Su.p -d b ' h

. ,bporte !y t e nm without touching the bottom. A I-liter beaker taIler

than thelsecond was placed in the latter and filled with alcohol, thespace between. the. two being :(111edwith solid carbon dioxid. A glass

~ube 3° :mm. III dIameter and closed at the bottom was fitted into theInner be

j

ker with a large cork, the tube being abou tone-third filiedwith a m xture of I volume of ,concentrated sulfuric acid and

3 volumesof absol te alcohol, and then nearly completely filled with absolute

ale.ohol.!

The temperature of the alcohol in the beaker was keptunIform. throughout by cons~ant stirring with a wire which passedthrough the cork and terminat~d in a ring surrounding the glass tube.A heavy glass spoon ana a glass spatula were placed in the aleohol.

When the temperature reached-5°°, the spoon was removed and

a .drop of the oil at once let fall upon it. A thin, solid, white, opaquedisc formed and was quickly made to drop into the inner tube by usinuthe glass spatula. The disc of solidified oil settled through the absolut:alcohol to the denser liquid below and there remained in suspension.

The beaker which had contained carbon dioxid was replaced byanother and the temperature allowed to slowly rise. An alcohol ther-

m~meter !was used for reading the temperatures below the freezingpOInt of tercury. Above -38c a delicate mercury thermometer wasemployed.1

.As th~ tempe.rature r~se the!disc remained unchanged until at -I9'J

It began tq lose Its opacity. At -140 it had become perfectly trans-parent, bu~ no cbange in shape could be detected below --

TId"

. . I. IeISC was .~uc.h contracted and thickened at -5:1 and became entirelysymmetnc~1 In form at -2.3°. A second determination gave practicallythe same rfsults, the final reading being

-2.4°. The change in tempe~-ature (Wher

..

near the melting ~oint) required5 to 6 minutes for one

degree. I!'

To determine the change i4 the consistency of the oil, a thin-walltube of 8 fm. diameter, closed ~t the bottom, and containing I em. of---.

J U. S, Dept. of Agr., Div. of Chlfm. Bul. (1895) 46,34.

172 BULLETIN NO. 53. [Jury,

the oil, was placed in alcohol at -45 J. After the oil had become solid a

glass rod 20 em. long and 2 mm. thick (the lower end being widened to

5 mm. diameter) was placed in the tube so that its weight was entirelysupported by the solidified oil. At -130 the oil had become trans-parent but still supported the rod. At -100 the rod began to settleappreciably and at -9° it had passed through the centimeter of oil tothe bottom, although a disc of oil suspended beside the tube in thesame liquid had not changed appreciably in shape. The change oftemperature from -10° to -9° required 5 minutes.

Iodin Absorption.-- The method of HiibP was employed for thisdetermination, except for certain details of the process.

Standard sodium thiosulfate solution was prepared by dissolving47.2 gms. of the crystallized salt (N a2 S203 5H2O) in water and dilutingto 2-liters. From theory 1 cc. of this solution should be equivalent to12.06 mgs. of iodin if the salt were pure2. The solution was standard-ized with resublimed iodin with the following results:

Iodin taken. . .. .. . .. .. . . .. .. . . . .. ... ... 0.5160Thiosulfate solution required. . . . . . . . . . . .. 42.9Iodin.equivalent to 1 cc I'l.03 12.01 mgs.

0.5574 gms.46.4 cc.

The average of thest: results, 12.02, was used in the following'work:

The iodin solution, containing 50 gms. iodin and 60 gms. mercuricchll)rid in 2 liters of alcohol, was standardized whenever used.

Little pipettes of about 0.5 cc. capacity were placed in 5 cc. vialsnearly filled with the corn oil, the bulb of the pipette being immersed,and the whole weighed. The measure of oil was then transferred to a

500 cc. glass stoppered bottle, the pipette returned to the vial, and theexact weight of oil taken determined by difference. The duplicate istaken immediately and necessitates only one more weighing. 10 cc. vfchloroform and 40 cc. of iodin solution were added to the oil. After2 hours 25 cc. of 10 per cent. potassium iodid solution and about 125cc. of water were added and the excess of iodin determined by titratingwith the sodium thiosulfate solution, starch indicator being added nearthe close of the reaction.

Duplicate determinations of four different samples of oil from asmany different sources gave the following results:--

1 Journal Society Chemical Industry (1884) 3, 641.

2Sutton's Volumetric Analysis, (1890) II5, states that standard sodium thiosul-

fate solution may be made by simply dissolving an exact weight of the crystallizedsalt, Na2 S203 5H20, in water and diluting to a definite volume.

~.

1898. ] CHEMISTRY OF THE CORN KERNEL.J73

Oil taken.gms.

1 \0.3473. . . . . . . . . . . . . . . . . . . . . . . . .I o. 3844

2 ""'"{ ~::;~~

Iodin absorbed.gms.

0.42550.4729

0.51790.5729

Iodin absorbed.per cen t.

122.5123.0

121.8

121.5

\ 0.42813. . . . . . . . . . . . . . . . . . . . . . .. ./ 0.4742

0.52120.5772

121.7121.7

l' . . .. . . . . . . .. . ..""

.l. ~o.

43~~ 0.5324 123.1I

. (0.51 0.6351 122.9

dxygen Absorption.--In order to afford a large surface for the

absor~tion of oxygen, the oil was placed in a low crystallizing dish of

75 mlI1. diameter. This was allowed to stand at the room temperature,the weight of the oil being determined from time to time as follows:

Weight of oil taken 2.1732gms.

o/eight after 1 day ',""''''''''",,,,,,,,,,,,,,,, 2.1722

"II

7 "days. . . . . l ..""""""""""""",

2. I 7 ISI" "II '.

""" , 2.1718! II 1012I "'''1'

2.1718

h IT, ese results confirm ~hose of Spiiller, showing that the oil doesnot ta~e up oxygen under th,ese conditions.

The dish was then plac~d in a water Oven and the following datalobtained: :

Weight after 1 hour .,............................1 day """"'"

"2 days...................................

2.1726 gms.

2.1996

2.2488

2.2590

2.25882 . 2558

2.2513

2.2448

3

4

56 "7

""0"'.'","0""'"""""""

""""""

""""

"'" '.""""'" """""'.

'"... .

'" """""

"""""" """""'"

'"".,

. T1e first action of. air upon the hot oil .is evidently the direct addi-tIOn ofi oxygenj but after 2 <;>r3 days the oil began to turn noticeablydarker ~n color and finally tq lose weight, evidently due to a secondaryreactio? which effects some decomposition of the oil with formation ofvolatil~ products.

Le'ctlhin2.-A weighed quantity of oil was mixed with potassiumnitrate itnd sodium carbonate in a platinum dish and ignited until thecarbon ,was completely burned. The fused mass was dissolved in dilute

+.

1 T~ese results e.m~hasize the. importance of avoiding the presence of oxygen indryrng c<!>rnor corn OIllD analytic41 work.

2L~cithin is commonly regaraed as a compound of the base, neurine, with di-stearyl-g!ycero.phosphoric acid, although one or both of the stearic acid radicals maybe replaced by radicals of palmitic,or oleic acid, and the neurine (trimethylhydroxy-ethyl ammonium hydroxid) is sometimes replaced by another base; e. g.. betaine.

174 [.fitly,BULLETIN NO. 53.

hydrochloric acid, and the total phosphoric acid determined]. Theamount of lecithin was calculated by multiplying the weight of mag-nesium pyrophosphate obtained by the factor 7.25'!. Duplicate deter-minations gave the following results:

Oil taken , .10.728

KNO, used'. . . .. . .. . . . . . . . . .. . . . . . . . .. .10.0Mg2P.07 obtained 0.0221Lecithin .. ..,.. ,.. 0.1602

Lecithin in oil' 1.49

6.435 gms.

35.00.0132

0.0957

1.49 per cent.

. Cholesterol".-To determine cllOiesterol6about 5° gms. of the oilwere saponified on the water bath with 20 gms. of potassium hydroxidand 100 cc. of

7°per cent. alcohol. The soap was transferred to a

large separatory funnel with 200 cc. of water and shaken first with5°°

cc. of ether and then 3 times with 25° cc. of ether. The four portionsof separated ether were combined, and the ether distilled, the residuebeing resaponified with 2 gms. of potassium hydroxid and 10 cc. of 70per cent. alcohol. The solution was then transferred to a small sep-aratory funnel with 20 cc. of water and shaken with 100 cc. of ether.After separating the aqueous layer the ether solution was washed fourtimes with 10 cc. of water, the ether solution being finally transferredto a weighed flask, the ether distilled and the weight of the dry residue(cholesterol) determined. Three determinations gave the followingresults:

Oil taken. .. .. .. .. .. . .. .. . .. 50. 1(j

Cholesterol obtained. . . . . . . .. 0.7002Cholesterol in oil. . . . . . . . . . .. 1.40

53.500.71 Lfr. 33

54.24 gms.0.75121.38 percent7

The cholesterol was recrystallized from absol ute alcohol in charac-teristic glistening plates, melting at 137c to 137.5°. It also gave thecharacteristic color reactionsS for cholesterol: I, when shaken withchloroform and sulfuric acidj 2, when evaporated to dryness withnitric acidj 3, when warmed with hydrochloric acid and ferric chlorid.---

'Cf. Hoppe-Seyler. Jahresbericht uber die Fortschritte der Chemie (1866) 744;Schulze and Frankfurt, Landwirtschaftliche Versuchs-Stationen (1893) 43, 207.

27.25 parts of lecithin (CHHooO.PN)yield I part of Mg. P2°7'

'The proportions of KNO" used were purposely varied, but the results indicate

that the smaller proportion was sufficient.

'By extracting corn with ether and alcohol, successively, Schulze and Frank-furt (reference above) have obtained amounts of phosphoric acid equivalent to 0.25

to 0.28 per cent. of lecithin in the corn.5A monatomic alcohol, C2.H.,30H.

.Cf. Bi>mer, Zeitschrift flir Untersuchung der Nahrungs- und Genussmittel

(1898) 21, for recent work on the details of this method.

7Spiiller had obtained 1.35 per cent. and Hart 1.55 per cent. of unsaponifiable

matter.

"Watt's Dictionary (1889) 2, 147.

:or,

1898.] CHEMISTRY OF THE CORN KERNEL.[75

Total Fatty Acids.-After removing the cholesterol from about .0

g~s. of oil the remaining soap solution (about5°° cc.) was acidifi~cl

WIth hydrochloric acid and shaken in a separatory funnel. An ethereatlayer of about IS° ce. at once separated. After adding 100 ee. moreether and thoroughly shaking, the aqueous layer was drawn off theether s(JIution of the fatty acids was washed with several portio~s ofwater af.d then. transferred to a weighed Ilask, the ether distilled off, afew cubr centImeters of abs9lute alcohol dissolved in the residue andevaporated to remove traces <pfwater, and the weight of the total fattyacids dbtermined . :

i.

oil taken-:

. . . . . . . . . . . . . . . . ."

. . . . . . . . . . . . . . . . . . . . . . . .50. roo gms.Fatty acids obtained. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46.915

Farty acids in oil -"" ...93.5; per cent.

ThJ fatty acids form a solid mass at IS°, but melt nearly corn.plet~ly ft one or two degrees, above, the last particles of solid disap-peanng ft 230. Prepared as idescribed the fatty acids abso rbed onty

126.4 P9r cent. of iodin instea1 of 13°.7 per cent. as calculated from theiodin abrorption of the oil. This indicates that oxygen had been ab-sorbed br the acids during thel, process of separation. It was found thatoxygen is slowly absorbed by the fatty acids while standing in a desic-cator at .the ordinary temperature. At 100° the absorption is muchmore :apId although, as with the oil, secondary reactions soon begin atthe hIgher temperatur.e. The change in weight was found to be asfollows:

Time,in days.

Weight of fatty acids, gms.,

in desiccator. in water oven.o. . ,. . . . . . . . . . . . . . . . . . . . . .

- . . . . . . . . . . . . . . . I .9685

I. . . . . . . . - . . . . . . . . . . . . . . . . . . .."""""

1.96922. . i . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . .

- . . . . . I .9717

3. . fH . . .. . . . . . . . . . . . . . . . . . .. . . . . . . . .. . I.9777

4.. ,.. . .. .. '''''''' ...''''''''''''

I. q8478. . i

". . .. . . . . . . .. . . ... . . . . . .. . . .

'". . . 2 .~23r

:~: : ! : : : : : : : : : : : : : : : : : :

.

. :

.

.....

. . . . . . . . . . . ., .2.0665. . . . . . . . . . . . .2. 0<)1I

22.., . . .. . . . . . . . ."

. . . . . . . . . - . .. . . . ., . . . . .2.115728..

"""""""' 2.129334..

"""""""""' 2. 1297

.All altio~ apparently ceased after about one month's time. A con-

sIderable 1I>0rtlOI1of the fatty acids had separated in the solid form andof a pure rhite color, while the other portion remained a colorlessoily liq~idf

. ii- J

It IS of mterest to not,e thie apparent relation between the iodinabsorptio~ and the oxygen absorption by the fatty acids. As alreadyshown the .fatty acids as prepared absorbed 126.4 per cent. of iodin.If an equivalent amount of the bIvalent oxygen may be absorbed instead

2.2740

2.3106

2.33662.3366

2.3282

176 BULLETIN NO. 53. [Jury,

of the univalent iodin, then 8.0 per cent. of oxygen should be taken up.The results show that 1.9685 gms. of the fatty acids absorbed 0.1612gms. of oxygen, an amount equal to 8.2 per cent.

Time would not permit the preparation of the fatty acids in amanner which would prevent the absorption of oxygen during theprocess, a~d then a repetition of the quantitative determination of theabsorption. This is especially desirable in order to confirm the resultsas given above, and the writer expects to investigate this point morefully in the near future.

VolaNle Acids.-About 5 gms. of oil were saponified in a 500 cc.flask with 2 gms. of potassium hydroxid and 40 cc. of 80 per cent.alcohol. After evaporating the last of the alcohol, JOO cc. of recentlyboiled water were added, the soap solution acidified with 40 cc. of dilutesulfuric acid (I to 10), a few pieces of freshly ignited pomace stoneadded, the flask connected with a condenser by means of a safety bulbtube, and 110 cc. of distillate collected. After mixing, 100 cc. werepassed through a dry filter and titrated with one-twenty-fifth normalbarium hydroxid solution.

Four determinations gave the following results:

Oil taken. . . . . ..""""N/25 Ba (OH), required.

4.5061.3

5.894

1.5

5.671

1.4

5.718 gms.1.3 cc.

As two blank determinations required I. 3 and 1.5 cc., respectively,of the barium hydroxid solution it is evident that the oil contains novolatile acids.!

Separation and Determination of Fatty Acids.-It has been foundespecially by Hazura2 and his associates that the oxidation of unsatu-rated fatty acids by alkaline potasslUm permanganate serves as a basisfor the approximate separation of several fatty acids. Under properconditions the oxidation is chiefly confined to the direct addition of thehydroxyl group (OH) wherever" free valences" exist. The followingshows the relations among several acids in the series containing eighteenatoms of carbon in the molecules:

Saturated Acids.Stearic. C1.H..02.

Oleic, C,.H..02' oxidizes to... .dihydroxy stearic, CuH..(OH)202'Linolic, C I.H'20., oxidizes to. . tetrahydroxy stearic. CuH",(OH).02'Linolenic, CI.H.o020 oxidizes to. hexahydroxy stearic, CI.H.o(OH).O..

Unsaturated Acids.

-----ISpiiller gives Reichert's number for the volatile acids as 0.33; Smith states

that the oil examined by him contained volatile acids equivalent to 0.56 per cent. ofKOH; and Morse (New Hampshire Experiment Station Bulletin (1892) 16, 19) givesvolatile acids as 3.2 per cent. in a sample of corn oil which absorbed Il2.8 per cent.of iodin.

2Monatshefte fiir Chemie (1886) to (1889), Vols. 7 to 10.

'Cf. Hazura, ibid. (1887) 8, 269.

1898.] CHEMISTRY OF THE CORN KERNEL.[77

After .removing the cholesterol from53.5 gms. of oil, the combinedsoap s~lutlOn was heated till the dissolved ether was distilled cool d

and dIluted to 2 liters. Two liters of a ' .e ,1.5 per cent. potassIUm

permanganate solution were then graduall y added WI' th co t t t. .

Af', ns an s Irnngter 10 mInutes the p~e~ipittted manganese hydroxid was filtered off;and the ,clear filtrate aCidified with h ydrochloric aCI' d 'f]

. .h f

. 1e precIpitatet us orred wa~ filte:ed off, "lashed, air-dried, and then extracted wi thether. !fhe residue msoluble,in ether wei g hed af ter dr .

8I ' '" i 'ymg, I gms.

t was eF~racted With boIlmg ,water until but 2 gms. remained, whichwhen agflIn extracted with et~er, left a residue of only 6 d

soluble in boiling water.'

o. gm. an

.T~e substance dissolved in hot water was practically completelprecipitated as the solution cooled1 and

Prove d to b'

t ".dY

( d e sa I VIC a CItetrahy; roxy stearic acid), as is indicated by the methodOf f r . t

.d b't I b ' l '

. 0 ma IOnan y I,S so u Iity In hot water. The melting poine of the dried sub-

stance ,as I57~-1~9°' .1. T~l

quant~tatlve synthesl~ of the potassium salt was effected by

d~ssolvI~g a weighed amount 9f the acid in warm alcohol and titratingwith sta1dard alcoholic potassium hydroxid solution:

I

Sativic ~cidtaken.1.000

Potassium hydroxid

required. '0.1604

Per cent. potassium

in product..

10.08

Per cent. potassium

(theory) 1

10.14

The ether ~ol.utions obtained as described above were combineciand the ether dIstIlled, The residue was solid

at the roo tm en1 perature,melted gradually as the temperature rose from

40 ° to 6 0 , jf

0 , ane waso~nd .to absorb 79.2 per cent. of iodin, thus showing very incomplete

OXidatIOn of the unsaturated acids.A s~cond lot of corn oil (54.24 gms.) was oxidized by alkaline

per~angfnate, the cho,l:sterol and then the dissolved ether having beenpre~lOusl!y re~lOved. llle soap was diluted to 2 liters and cooled to OUby Ice kl

lept In the solution. A solution of

potassl ' um, . ..' permang~na.tec~n~aInlIlg 80 gms In 2 lIters Of water was slowly added with constantstIrflng. ! After

3° minutes precipitated matter was filtered off a.ndwashedj the clear filtrate was acidified with 1

5° cc of t dh d ..' . concen ratey rochl?T!c aCldj the precipitated acids were filtered ffd

.d dt d'

0, ne, anex racte 'wlthether. The residue insoluble in ether (17.7 gms.) was

.12000icC of the filtrate from the precipitated sativic acid required only 0

5 cc ofN/5 KOH

f

'to show alkalinity with prenol phthalein. . .

. 'Bau. rand Hazura, Monatshe~te fur Chemie (1886) 7, 225, give 1600 as tbemelting pOl t of several samples of ~ativic acid, prepared in a manner

S. .

1 tthe above. I 1m1 ar 0! ,

'Calculated weight = 1.000 + o!. 160439.14 - 1.008

. F C ( ! 56. 148or ..H't OH), O.K.

178 BULLETIN NO. 53. [Jury,

dissolved in boiling 95 per cent. alcohol. On cooling. the sativic acid

separated in the crystalline form, melting at 16[0-r63'-.By distilling the ether from the solution obtained as above

described, a brown residue (9.5 gms.) was obtained which melted at 55°to 000 and showed an iodin absorption of only 9.2 per cent.

The aqueous acid solution from which the insoluble organic acidshad been precipitated by hydrochloric acid was evaporated nearly todryness, a black tarry mass gradually separating, showing that, althougha small amount of unsaturated acids had been unacted upon, the oxida-tion had gone far beyond the simple addition of hydroxyl groups to theunsaturated compounds.

To further investigate the fatty acids, a method essentially that ofMuter' was tried for their separation and determination. It is basedupon the fact that the lead salts of the unsaturated acids, oleic, linolic,etc., are soluble in ether; while the lead salts of the saturated acids,stearic, palmitic, etc., are not.

About 1. 5 gms. of the oil were saponified with alcoholic potash and

the soap dissolved in water, the unsaponifiable substance (cholesterol)being separated from the soap solution by shaking with ether. Thesolution was then neutralized with acetic acid, and the fatty acids pre-cipitated with lead acetate, a slight excess being added. The lead saltswere washed with water, and then transferred with 5° cc. of ether to aglass cylinder of about 60 cc. capacity, which was stoppered and thenviolently shaken for 5 to 10 minutes. The small quantity of matter in-soluble in ether was then allowed to settle. A stopper carrying twoglass tubes similar to those used in the ordinary washing bottle wasplaced in the cylinder, the long tube reaching nearly to the undissolvedsediment. By blowing in the short tube the clear solution is transferredalmost completely without disturbing the sediment. The undissolvedsubstance was then shaken with more ether, allowed to settle, and theether transferred as before as completely as possible. This treatmentwas t~ice more repeated. The undissolved lead salt was then warmedwith about 25 cc. of dilute hydrochloric acid, till the fatty acids sep-arated; and, after cooling sufficiently the whole was transferred to a 25°cc. graduated bulb tube, ether being used to complete the transfer.The portion of the tube below the bulb contained 50 cc. and wasgraduated to 0.2 cc. A small glass tube carrying a stopcock was sealedin just below the 5° cc. mark. The tube was filled to the 25° cc. mark(above the bulb) with ether, and thoroughly shaken. The aqueouslayer, containing the excess of hydroch loric acid and the precipitatedlead chlorid was allowed to separate.

The volume of ether solution was observed, and 200 cc. of it were

'Analyst (1877) 2, 73.

1898. ] CHEMISTRY OF THE CORN KERNEL.179

drawn off into a weighed flask, evaporated to dryness, and the weight ofthe residue determined.

Duplicate determinations gave the following:

Oil taken.. .. .. . .. . .. . .. .. .. .. .. . 1.600 1.610 gms.V91ume of ether solution.. .222.4 221.0 cc.E~her solution taken """" ,'.,. .200.0 200.0 cc.S,,:turated acids obtained. .. , 0.0670

0.0648 gms.Saturated acids in oil 66, .. ...,.

""""'"4. 4.44 per cen t.

Thr residue of saturated jacids formed a white solid mass. It wasdissolvep in hot alcohol and lallowed to crystallize. The melting point

,:as 57°:. The quantity of the saturated acids thus obtained was con-sIdered fOO small for further satisfact'Jry examination (see foot notebelow). ,

IBefpre the lead salts of the saturated acids were completely washed

by decaeation' the clear ether solution of the lead salts of the unsat-urate.d al~ds abs~rbed oxygeni and became cloudy, a white precipitateformIn~ IIn consIderable am9unt. Two samples of the atmosphere inthe cyh~de~s above the soluti~ns were drawn off in gas burettes; and,after removIng the ether vapQr, the residual air was found to containonly 15.3 per cent, and 13.9 per cent., respectively, of oxygen insteadof 20.8 per cent. as found in the air of the laboratory.

By subtracting the percentage (4.55) of saturated acids found inthe oil from that of the total fatty acids (93.57) the amount of total

unsat.ura~ed a~ids is found to be 89.02 per cent., consisting of oleicand hnohc aCIds. (Th e melting point of the sativic acid obtained andthe composition of its potassium salt prove the absence of linusic acidin the products of oxidation, and, hence, of linolenic acid in the totalfatty acids.)

Fr01 the iodin absorption, the amounts of oleic and linolic acidscan be accurately determined. Thus:

Olei~ acid, ClBH340, + I.= C,BH,.1202' diiodo stearic acid,Lin91ic acid, C'UH320, + 2q = C'BH'21.02' tetraiodo stearic acid

I .

. ~s 89.02 ~ms. of these uns'aturated acids in the ratio in which theyeXIst In corn 011 absorb 122.3 gms. of iodin, the following equation can

be stated" x being the number of gms~ of oleic acid:

II 254' 508I x 282+ (89i.02- x)

280 =122.3

--~leJst two days'time is reqU

r.

i.red fo, this process, and even this was foundmore. satisf~ctory than filtration. 1 ave no doubt that, if centrifugal force weresubs!ltuted

1

0r gravity, the washing b decantation could be done much better and soquickly tha~ the unsaturated acids coud also be determined before the absorption ofany apprecl,,;ble amount of oxygen, Quantities of the separated materials sufficientfor f~rther examination could doubtl~ss be obtained in a short time. No suitablecentnfuge was at hand for this work.

180 BULLETIN NO. 53. [Jury, 1898.

The oleic acid is found to be 42.92 gms. and the linolic acid 46.10gms. . .

By subtracting from the amount of saturated aCIds the equIvalent

of the >stearic acid contained in the lecithin, and calculating to therespective glycerol esters the remaining saturate.d acids (as st~aric a~id),

the oleic acid, and the linolic acid, the followmg summary IS obtamedas the composition of the oil of corn:

UNIVERSITY OF ILLINOIS

Cholesterol. . . . . . . . . . ., ............................Leci thin. . . . . . . . . . .. ...Stearin (?) ., ...,. ............................Olein , .,. ,..

Linolin. . . . . . . . . . . . . . . . . . . . . . . . . .: ................

1.37 per cent.1.49 "3.66

"44.85 "48.19 "

AgriculturalI

-Y II,

~xperiment Station.

URBAN~, MARCH, 1899.

Total. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 99.56

C. G. HOPKINS,PH. D., Chemist.BULLETIN No. 54.

\SPRA YING APPLE TREES, WITH SPECIAL REFERENCE TO,

I

I, APPLE:SCAB FUNGUS.

-~, ~- -,'~"--

About eight months ago the Horticultural Department of the Illi-nois Experiment Station issued a bulletin on orchard cultivation, whichclosed with these words:

". . . . while other things have greater or less

effect upon an orchard's health and condition, the prime requisite tosuccessful orcharding in IJlinois is thorough and systematic cultivation."But while cultivation is the ptime requisite, it is, after aJl, but onerequisite, albeit the chief; for besides the struggle for the conservationof moistu're in his orchard du~ing drought, the orchardist bas alwayswith him Jthe struggle against the insects and fungous diseases whichprey upo~ his trees and fruit. The object of the present bulletin, then,

is to assist the Illinois fruit grower in his fight against these active ene-mies of th~ orchard, and to point out to him, if possible, the best andmost effective means of warfare.

The tro enemies most I 'enacing to the apple growing industry ofIllinois are the apple scab fungus and the codling-moth. They, in turn,find their imost deadly foes in Bordeaux mixture and Paris green. Alittle inves'ti gation will readily d~,termjne whether or not it is worth while

I I

for the llIir.°is apple grower to invest in spraying machinery and beginthe work of exterminating, or atl, least checking, these nuisances.

,IRr