Life on Other Worlds Must Be Mucht

the Same as on Ours, Declares a Dis¬tinguished French Scientist, ExplainingHowMinute Life Germs Can Make,Un¬harmed, Prodigious Journeys ThroughColdest Space.

PROFESSOR ALPHONSE BERQET, oi the

Purls Institute of Oceanography, baewritten nn art'^le supporting the theory

that life originated on the planets through mi¬

nute living germs which are carried throughspace and fall upon the surface of these planets.Professor lierget, one of the moBt distinguishedof European scientists, takes up ind answers

*11 the objections to this theory raised in

recent months. He makes tho importantstatement that if '.here 1b life in other planet*of our jlur iystena 11 mu6t be like'that upon

earth, and not the weird fanstastlc monsters

lmugin»'.t . bcience has heretofore conceived.Professor ' ergot begins his article by calling

attention to the fact that "no question has more

disturbed the mind of man than tha* of findingout whence come the earth and her Bisterplanets; whence comes the sun. toward whotgoal In It carried by that slow evolutlou that Itundergoes arid how came life uj>on earth?"

Hr- gives an elaborate explanation of the f..a-place theory.that our solar system was firstan Incandescent nebula. This n<-fcn;Ia, contract-In?; through lis gradual loss of heat, becamecondensed Into an enormous fiery and gaseoussun. This sun. whirling nt terrific rate, threwofT. as It condensed further, the planets.

His article from this point Is as follows:

By Prof. Alphonse Berget,of the Paris Institute of Oceanography.WE know toilny that the Laplace theory

must be modified In some points. Asm whole, however, it Is still In force.

It Is enough, therefore, to reconcile It with thenew conquests of science; that is what the Il¬lustrious physicist of Stockholm, ProfessorSvaute Arrlienlus, has doneTho Swedish scientist Introduced into the

theory of the evolution of worlds u second forcen.» necessary to consider a.< universal gravita¬tion, that 1», the pressure of radiation or oflight, the conception of which Is due to J.Clerk-Maxwell, and the reality of which hasbeen demonstrated by the experiments of Lebe-deft. This pressure is exerted upon every sur¬face exposed tu light aiid generating light.

l he attraction of gravitation Is dependent onthe mass of an object, but the pressure of radia¬tion is dependent on the extent of the surfaceof the object. One can readily conceive, there¬fore, that in the <as»- of very attenuated parti¬cles ot matter the repelling pressure <jf lightmay exceed th>- iittractlve force of gravitationOn tiny particles whose diameter would

amount to ns little as the 0.0001G of a milli¬meter, the pressure of radiation would be tentimes as great as the attracting force We havesuch small dimensions in the spores of bacteria.The s Igbtest wind carries them oil Into theatmosphere and may even take them to Itslimits. 100 kilometers, where the pressure ofthe air is not more than a very small fractionof a millimeter of mercury

It is this pressure of radiation that Arrhenlushfis given a place in the formation of worlds.It drives away from the stars the fine "cosmicdust which tli«* constant eruptions upon themthrow out every moment The expelled parti-

cles bear a negative electrical charge. Theyare going to coiue la contact with these cold,gaseous masses of rarified molecules, contain¬ing helium and hydrogen, called nebulae.These nebulae contain a very small number ofmolecules; hence their low temperature. Whenthe electrically charged particles reach them,'he former make the outside luminous, undthen these nebulae arc visible to observers onthe eartb.The dust, which Is condensed Into meteorites,

becomes centre-" of condensation for nebulae.I>»t a dark foody, such as the moon i« to-day,such as the sun will br- later, happen to pene¬trate into such surroundings in the course oflis wanderings, lasting myriads of centuries, itwill become still more eusliy a centre aboutwhich nebulous matter would accumulate. WhileIt becomes heated, the nucleus becomes incan¬descent. a sun will be born

Finally, let two dark suns collide in the In¬finity of space and time; the violence of theshock is enough to volatilize their matter; th<*breaking of their envelopes would release theIgneous matter so long imprisoned beneaththeir cooled crusts. Like two gigantic shellsthey "explode" and the compounds tbat theircentres contain, held under enormous pressures.Met free masses of gas that escape in spiralaptirts. Then the stages of which I.nplaco con¬ceived f .n begin to follow each other. Gener¬ating planets are generated from one or twoof the nuclei that exist In the midst of thenebulous spheres surrounding them. We havowatched the resurrection of a world.These collisions are not Idie hyi»othesea. Wewitness them in the heavens each time that a

new star appears. It is a perpetual cycle thatre ommences in this manner, a cycle the mech¬anism of which has been pointed out for thefirst time by the brilliant genius of Arrheniu-uSuch is, too briefly summarized, the Swedishphysicist's principle of the theory of cosmogony.Hut lie has not been content with explainingthe evolution of "cosmic" matter.He has asked himself.and it is this that

will Interest tho rc-adurs more especially.howlife could appear on a world thus created. Hehas tried to Una out whether living germs,having left a world where they found theirconditions of existence realized, can endurethe long journey through space and bring toanother world the germ of life which is inthemselves, thus becoming the starting pointof a series of living beings brought slowly, byan evolution parallol to that of the piauet thatsustains them, to gradually increasing degreesof perfection; in a word, to "higher" states.toman.Svante Arrhenlun answers this question bjwhat ia tailed the doctrine of pansperm>, adapt¬ing it to the most recent advancement of mod¬ern physics. Panspermy is not new; Richter

was the llr.st to advance It, about 1865. LaterIt received the distinguished support of the il¬lustrious English physicist. Lord Kelvin, and laGermany Helmhoitz lent it the aid of his greatauthority.In Its first form, this doctrine assumed thatmeteorite.-?, fragments resulting from the col¬lision between two dark bodies of the heavens,come in contact with a world and bring there

germs that the explosion has not had time todestroy; as, when one blows tip a quarry withdynamite, certain pieces of rock may roll tothe »tr>t?o:n of th* mountain, remaining cov-

Dr. Svante Arrhenius, the Exponent of the Hypothesisthat Life Was First Sent Through Space to Our Planet byLight.

rred wltb vegetation, with living germs thathav»> stayed intact. Under these conditionsineteroritei could admit of organic "inclu¬sions," which could carry life to celestialbociiei yet devoid of it.However, examination of the hypothesis In

tbis very simple form raises objections, theprincipal of which is the stupendous tempera¬ture to which the germs would be immediatelysubjected. Mertlv the sudden stopping of thoearth in its motion, even without the lnterven-:ion of h collision, would suffice to volatilizeits matter as n result of tin* quantity of heatliberated. If, in additiort, there should be hcollision °f two celestial masses with the libera¬tion ot the fiery matter composing their respec¬tive nuclei, it is almost certain that not a livingorganism would escape this beat manifestation*which would reduce all to gas. it is. then, verydifficult to admit of the conveyance of germsby meteorites considered as "fragments" froma celestial cataclysm.Arrhenius has completely modified the hypo¬thesis of Panspertny by adapting it to the de¬mand? ami achievements of modern physics.He has considered the possibility of the con¬

veyance of germs themselves, hide, endently ofall mineral aid. and this by bringing into playthe "pressure of radiation," of which we havespoken In the beginning of this article.By direct, measurement the pressure of radia¬tion on a spherule the 0.0001»» of n millimeterfn diameter (or 0.16 of a micron) might be tentimes as strong as the attractive force resultingj iciftai gravitation. Now germs ofthese reduced dimensions do exist. Botanistsknow for a certainty that the spores of manybacte-'ia have a ulameter of 0.3 to 0.2 of amicron, and that beyond doubt there exist some

even much smaller. The progress of the ultra-microscopy is neginning to enable us to koothese germs of the order of one-tenth of atnicron in size.Let us imagine such a inlero-orgnnlsm EweptnfV the surface of the earth bv a current of 1r

Chat carries It as far lib the higher atmosphere,»ay to the altitude of approximately a hundredkilometers. When It has reached that point ItLs subjected to another category oC forcea hub-

ceptlhle of acting on It; these are foreefl of anelectrical kind.

It Is. indeed, at about that altitude thatradiations produce polar auroras. These nur»-r:ih are caused by the arrival into the atmo¬sphere of the earth of cosmic dust coming fromthe sun and driven from It by pressure of radia¬tion. This dust Is charged negatively, and Itsdischarge makes luminous the region of theatmosph<*vo in which It is. Under these condi¬tions, if a spore coming from the earth's sur-t.'ice is ulso negatively charged by contact withth<v electrically charged dust, it may be re¬pelled by the latter, which will drive it to¬ward intersidereal space by what iB knownas electrostatic repulsion.We have our germ, then, started on ita

journey Into space. What will be the condi¬tions of time of such a journey? On its waythe gerin will be caught, In the neighborhoodof a celestial body, by somo larger particle ofthe order of size of a micron, which forma aportion of that dust scattered profusely aroundthe solar systems. Once carried away by itapartlclc, which, because of Jtsgreater size, Ismore subject to the action of gravity than tothat of the repelling force, it can then pene¬trate Into the atmosphere of the planets lhakit will happen to encounter.

If wo assume that this travelling germ hash density equal to that of water, which is un¬questionably accurate for living germs, wefind that it will need nearly twenty days for ItSo reach the planet Mars, eighty days toJupiter, fifteen months to the planet Neptune.These are only platets forming part of ourown solar system. Ifwe try to find the timenecessary fci this germ to reach the solarsystem nearest to ours, that ls, the systemwlioce' cont ml sun is the star Alpha, of the

constellation of the Centaur, we win find theduration of tlio journey to bo approximatelynine thousand years.How will our germ, living at the time of lti»

departure, act in the course of this long Jour¬ney?

Interstellar ppaco has a very low temper*-lure, i uear the absolute zero of tho physl-

which is 273 degrees centigrade l.elowthe temperature of melting ice. The germ thatis traveling across this space under the impulseof pressure of light must, then, endure formonths, years, or even centuries, a tempera¬ture of 220 degrees Centigrade below i-ero.What is going to be tho result from the view¬point of lta vitality, and. more than all, fromtho point of view of Its germinaUve power".'Modern physicist* and physiologists answer

this question victoriously. In the laboratoryof the Jenner Institute, In London, scientistshave quite recently met with success lu keepingIn liquid oxygen for twenty hours, at a tem¬perature of 250 degrees Centigrade below *ero,spores of bacteria which have completely re¬tained their germlnatlve power after this se¬vere test. And Professor MacFayder has keptliving germs for more than six months at 200degrees Centigrade below zero, not only with¬out their germinative power having been de¬stroyed, but eveu wlthcut Its having been In¬jured in the slightest degree.

Svnnte Arrhenius points out that this preser¬vation of germlnatlve power at very low tem¬peratures is the most natural thing i>osslble.This power, Indeed, ought to disappear onlyunder the Influence o* some chemical reaction.2nd it is known that these reactions take placemore and more slowly as the temperature ofthe medium is lowered. At the temperature ofInterstellar space, reactions of life ought to beproduced by an activity a thousand milliontimes weaker than at a temperature of 10 de¬grees Centigrade, and at a tempeiature of 220degrees Centigrade below zero the power of ger¬mination would not diminish more during threeinilllou years than It diminishes in a day at thetemperature with which we are familiar, 10 de¬grees Centigrade below zero.

All feRr in regard to the prolonged action ot(..old is therefore removed.it Is. then, withoutinjurious effect on the germlnatlve fuculty ofspores.

Time, actlnsf alone, seems equally harmless.Bacteria have been found, in fact, in a Roman

remain-..1 untouchedfor 1,800 years and which, nevertheless, weroperfectly capable of germluntion after this longInterval.

As to the inflqence of the absolute aridity olinterstellar space, an agency that is added toHint of cold and that of time, neither does thisappear to be dangerous to our germ of life.Shraider has shown that a greea algo, Pleuro-eoccus, can live three months in a medium thaihas been completely sterilized by sulphuricacid. Professor Maquenne. of tho Freuch In¬stitute, has gone still further. He has demon-

.11 -'vijeriment and observation athand, that seeds can stay several years in ai <es tube!.that is, in almost a completevacuum, without losing their germinative power.Paul Becquerel has carried his experimentsstill further. In the Leydcn laboratory he haisubjected bacteria and spores for three weeksto the combined Influence of vacuum, cold(.253 degrees Centigrade below zero), and ab¬solute aridity. Their vitality remained perfect.The "circumambient conditions" of intersid¬

ereal space are, therefore, not hostile to thevitality of a germ that would travel there, evenfor a very extensive period.

It is enough that among the thousand mill¬ions of thousand millions of gerra-s sent off Intothe Infinite by the pressure of radiation, a singleone shall reach a planet that has been withoutiit'e up to that time, in order to become theretho point of departure of manifold organismsthat will slowly evolve from it.The minuteness of such n germ moderates Its

fall through the atmosphere of this planetenough so that It does not become heated as aresult of lta friction in the atmosphere to a tem¬perature sufficient to kill It. Having enteredthe atmosphere of a new planet, it will followits eddies and currents, it will fall on a sub¬stratum. either solid or liquid, which will offerit conditions of development. Lift* will be bornon the surface of a world lifeless till that time.

Psychological Tests to Determine Abilities of School ChildrenBy Prof. Henry L. Weston, Ph.D.

HE ineihf.de of that comparatively newscience, experimental psychology,be employed very profitably in measur¬

ing tho ability of children and students to

A child has a certain capacity for learning,aud It is wrong to try to force that child tolearn more than its ability permits. Everychild has a special aptitude for some kind ofwork, and If that work is likely to furnish itwith a profitable livelihood it is most importantto discover early what the aptitude is and toencourage it. The«e capacities and aptitudescan be measured with something approachingscientific accuracy by the methods of experi¬mental psychology.The Binet-Simon tests for measuring a

child's true educational age are already wellknown. A new contribution to this branch otpsychology has just been made, A handy littlebook has been published which alms to supplyteachers with psychological tests that willenable them to measure tho educatlonul apti¬tudes of children and students. It is entitled"Experiments in Educational Psychology" (TheAlacmillan Co.). and Its author Is ProfessorDaniel Starch, Ph.D., of the University of Wis¬consin. The experiments are simple ones thatrequire no more apparatus than pencil andpaper.The ability of a teacher to hold a student's

attention and of the student to conccntrate hiss.ttention are, of course, of primary importancein education. T\vo little figures given by Pro¬fessor' Starch are very useful In measuring theetudeut's power of concentration.One figure suggests a book that la open. A*

you look at it thoughtlessly it appears alter¬nately to bo opened, with the printed pagetoward you, aud then with the cover towardyou. The student calls out "In" or "out" a.sthe changes appear to occur, and the teacherrecords the frequency of tho changes with biswatch. Till:; will show the natural tendencyof the attention to wander.Then the teacher tells the student to try to

think that the book is opened "in" and recordshow often his impression changes. This willmeasure the power of concentrating attention.Another figure used is tho circle with tha

learn.

Thinking This Picture of Babies to Be a HumanBrain Shows the Interpretative Tendency of theMind.Giving a Meaning to Tracing Over This Star llefore ftThis Blot Is an Exer- Mirror fs^ an Exercisc in "Trialcise in Interpretation. und Error' Learninc.

fixing Your Eye on ThisCircle Is a Test of Coaccntratlnjj Attention.l-'fie across It. The teacher first asks the stu¬dent to look at this and call out whenever hefinds his mind wandering from It. Then the

teacher asks the student to think how thickthe cross line is and how much thicker it isthan the circular line. In this way the atten-tiou should remain fixed longer than when theBtudent stared aimlessly at the figure and thoimprovement will measure the power of con¬centrating attention.One of the simplest and most useful testa ia

in the perception of letters and words. Manychildren will look at a printed page withoutseeing and understanding half what they readbecause they are deficient in perception. Crossout with short horizontal strokes all the E'sin the following table. Work as quickly asyou can without omitting any. Record thetime:F L E S M R E T H G A IT r> R E T T EBENUTROFAERBSESOTDKMIALCXEREBTAFEELBAFER1GEEEHRELWOBBCITONNEVBDESHDEWOl.liBYETHEEN Y L E lllTNBR E V E T A HWTOPEEFOCESRUOCKETTEEL ATE M TESTAE E Ll'OE PNETFOSEHISFDEKOYKEVNEEBBDAEDYET T E R P L> E TPLSEMDERAOREHTAFEMOCEBNBHWZBVOEZQXKBD

.

It has been calculated that the ability tocross out all these E's in thirty seconds is atest of mental efficiency in an adult. The samaefficiency should be shown by every one abovt»

(be age of fourteen years. Lielow that anallowance for Immature powers may be made.An important mental quality is to be able to

tliink quickly of associated subjects which aronaturally called to mind by any word. To testthis wrile us quickly as possible the oppositeto each word in the following list. Record thetime:

Strong DarkDeep Roughf<8.zy PrettySeldom HighThin FoolishSoft PresentMany (i ladValuable StrangeI.ate WrongRude Quickly

We find ordinarily that children ranking highfn one kind of ability are not equally superiorin others, but there are forms of ability whichare associated with others. It is useful to de¬termine what kinds of ability aro allied to onoanother, because this knowledge helps us tobring out the children's fullest powers. Korinstance, a child who makes good progress inhis English studies should be able lo learnforeign languages with something of the sarnoease.A teacher should use te>sts to determine the

ficuteness of vision and hearing of all childrenin his class, for defects in these two senses arothe principal causes of inability to acquireeducation at a normal speed.When a student's education is sufficiently ad*

vanced, 1t. is very interesting and useful to learnwild.i kuiit ot jni.ibcd ase called to mind bycertain sentences, and whether these imagesare auditory, motor or tactile. To determinetliis cover a selected list of words with a pieceof paper. Slide it down far enough to exposethe first word. Then, in a short sentence, writ©in your handbook an answer to this question:"What do you think of as soon an you see thatword?" For example, If tho word is "grass"it might suggest imagery at once of this kind:"I think of tho green appearance of a meadow."Or if tho word is "shoo" It might suggest suchan answer as this: "1 think of the pinching ofmy new shoe." Do not try to make a selection,but write down whatever comes to your mindfirst. Suppose you use forty words. When youhave written down tho answers, put the resultsin the form of a table showing how manyof the^ forty words aroused visual images, audi¬tory. motor, tuctilo, etc.There are three methods by which the doingof a definite act may be learned:fa) By trial and error.that is. by rnakfugrandom attempts until by chance tiouio at¬tempts are .successful.(lu Pv imitation.that Is, by observing thoperformance of tho act and then attempting to

copy It.(c) By reasoning.that is. by attempting tothink it out and then proceeding accordingly.Tho most fundamental of these is tho trialand error method. The acquisition of all motorcontrol Is accomplished primarily by thismethod. Tho others servo only as supple¬mental aids. For instance, in learning to

btrlke a ball with the bat the boy begins byattempting to strike It and keeps on until holearns to strike it with more or less certainty.An Ingenious method of demonstrating tho

trial and error method of learning is by whati3 called mirror writing. The apparent motionof a pencil in a mirror is the reverse of itsactual motion. Hence the attempt to guide apencil by looking at its motion in the mirror.leads to frequent errors. The quickness withwhich a person learns to overcome this ten¬dency to error proves his ability to learn manythings from experience.There is ono way of applying the test o!mirror writing: Draw eleven slx-polnted stars

on eloven pieces of paper, fasten a sheet to thotable, and sit in front of a mirror. By meansof a pencil trace with the loft hand the outlinaof the star over it, beginning at a certain spotand proceeding in a given direction. Recordthe time It takes to trace over the outline.Trace the remaining ten outlines and numberthem in the order you do them. Tho fre¬quency witu which your pencil leaves the lineof the star wilt show your tendency to error.The improvement, if any, shown as tho num¬bers progress will show how uuickly you nralearning by "trial and error."An important factor lu learning Is the abilityto establish associations between two classesof visual symbols. To test this a J-et of pagesmay be prepared headed with an imitationtypeN rlior keyboard, lunch letter of tho alpha¬bet is enclosed with a number in a circle.Below this keyboard Is the reading matterwhich Is to be transcribed. The task of thoexperiment consists in substituting the num¬bers for the letters in the spaces below andrecording the time. Tho experiment regularlyrepeatod. either dally or weekly, will be veryuseful In showing progress in tho ublllty tolearn.II we can mea«uro the powpr or appercep¬tion In a student we shall have a most valuableindication of his imaginative power and hishigher mental capacities. Apperception is the"manner In which we receive a thing into ourminds" (Professor William James). It includesall tho processes by which we read meaningInto sense impressions. One person calls anobject a useless stone; another calls It a fossilof tho carboniferous age. The two personsreceive the object differently; they give dif¬ferent meanings to the same sense impression*Each gives that particular interpretation whichin moat In accord with his particular montaimakeup.