SCIENCE · OCTOBER 18, 1901.] quoted above. If wecompare the bunsen andthe single tip curves, wesee that they do not agree in all respects. The eleva-tions due to the emission of

SCIENCEA WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE

OFFICIAL NIOTICES AND PROCEEDINGS OF THE AMERICAN ASSOCIATIONFOR THE ADVANCEMENT OF SCIENCE.

EDITORIAL COMMITTEE: S. NEWCOMB, Mathematics; R. S. WOODWARD, Mechanics; E. C. PICKERING,Astronomy; T. C. MENDENHALL, Physics; R. H. THURSTON, Engineering; IRA REMSEN, Chemistry;CHARLES D. WALCOTT, Geology; W. M. DAVIS, Physiography; HENRY F. OsBoRN, Paleon-tology; W. K. BROOKS, C. HART MERRIAM, Zoology; S. H. SCUDDEB, Entomology; C. E.

BESSEY, N. L. BRITTON, Botany; C. S. MINOT, Embryology, Histology; H. P. Bow-DITCH, Physiology; J. S. BILLINGS, Hygiene; WILLIAM H. WIELCH, Pathol-

ogy; J. MCKEEN CATTELL, Psychology ; J. W. POWELL, Anthropology.

FRIDAY, OCTOBER 18, 1901.

CONTENTS:The American Association for the Advancement of

Science:Section B (Phlysics): PROFESSOR JOHN ZELENY 585Section G (Botany): DR. ERNST BESSEY....... 596Membership in the Association......................... 602

Address of the President of the Anthropological Sec-tion of the British Association for the Advance-ment of Science, LI: PROFESSOR J. D. CUN-NINGHAM...................................... 603

Scientific Books :--Riemann's Die partiellen Differential-Gleichungender mathematischen Physik: R. S. W. Com-stock's Text-book of Astronomy: SIDNEY D.TOWNLEY..................................... 610

Scientific Journals and Articles........................... 613Societies and Academies:-

Section of Astrononmy, Physics and Chemistry ofthe New York Academny of Sciences: DR. F. L.TUFTS. The Elisha Mitchell Scientific Society:PROFESSOR CHARLES BASKERVILLE.............. 614

Discussion and Correspondence:An Institute for B-ibliographical Research: AKSELG. S. JOSEPHSON. Discord: PROFESSOR MAXMEYER. A Correction: WILLIAM J. Fox...... 615

Current Notes on Physiography:Mlt. Ktaadn; Norwegian Fiords; The Origin ofM1Ioels: PROFESSOR W. M. DAVIS.................. 617

T'he Phylogeny of the Toothed Whales: F. A.L.618Anthropology at the University of California ......... 619Scientific Notes and News................................. 620Univer.sity and Educational News...................... 623

MSS. intended for publication and books, etc., intendedfor review should be sent ta the responsible editor, Pro-fessor J. McKcen Cattell, Garrison-on-Hudson, N. Y.

THE AMERICAN ASSOCIATION FOR THE AD-VANCEMENT OF SCIENCE.

SECTION B, PHYSICS.

THE officers of this Section were: Vice-President, D. B. Brace; Secretary, JohnZeleny; Member of Council, E. L. Nichols;Sectional Committee, D. B. Brace, JohnZeleny, B. W. Snow, L. B. Spinney, E. L.Nichols; Member of General Committee,L. B. Spinney.A large number of papers of unusual im-

portance was presented before the Section,so that a keen interest was maintained inthe meetings to the very end. The au-thors of a number of the papers were ab-sent but had representatives who were fa-miliar with the subjects they presented, sothat beneficial discussions were possibleeven in these cases.On Thursday forenoon, August 29, the

Section met with the American PhysicalSociety, and on the afternoon of the sameday there was a joint meeting of SectionsA and B.The following are the abstracts of the

papers that were presented:1. 'A Spectrophotometric Comparison of

the Relative Intensity of Light fiom Car-bon at Different Temperatures': ERNESTBLAKER.The instrument used in this work was a

Lummer-Brodhun spectrophotometer, thecomparison source being an acetylene flame.

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The carbon studied was that of the fila-ment of the ordinary incandescent lampwith treated surface, on the one hand, anda similar filament with smoked surface onthe other. Temperatures were computedby means of the empirical relation betweenthem and the ratio of the resistances ofthe hot and cold filament, established by.Chatelier. *

Isochromatic curves showing the rise inintensity with the temperature were plottedfor various wave lengths of the visiblespectrum. These, taken separately, ex-hibit the form characteristic of bodies pre-viously investigated, such as platinum andthe artificially produced ' black body.'The temperature or its reciprocal as de-

manded by the received equations for radi-ation is nearly proportional to the loga-rithm of the intensity.The corresponding isothermal curves,

however, show the existence of the remark-able peculiarity noted by Nichols t in arecent paper. The selective radiation in theyellow, described by that author, is evenmore strikingly developed at the highertemperatures covered in these experiments.It exists alike in the case of the gray-sur-faced carbon and in lamp black and wouldlead us to classify carbon rather with themetallic oxides than with the black bodies,as regards the laws of radiation.

2. 'The Distribution of Energy in theSpectrum of the Acetylene Flame': GEORGEW. STEWART.The great value of acetylene not only for

illuminating purposes, but also in experi-mental research, makes the study of thedistribution of energy in its spectrum ofconsiderable importance. In the work tobe described, a mirror spectrometer andfluorite prism were used to produce thespectrum, and the radiometer of Nichols tomeasure the radiant energy. The mirror-

* Chatelier, Journal de Pltysique (3), I., p. 203.t Nichols, P7kysical Review, Vol. XIII., 1901.

prism device of Wadsworth was utilized,the main advantage gained being that theradiometer could be kept stationary. Thespectrum fell upon a slit mounted directlyin front of the fluorite window ofthe radiom-eter, thus avoiding the use of axny lenswhatever.The source of light used in the work

upon the visible portion of the spectrumwas a cylindrical acetylene flame from asingle-tip burner. This type was used be-cause the intensity per unit area wasgreater than in the flat flame. The results,plotted in the form of a curve, afford defi-nite data concerning the distribution ofenergy in the visible spectrum of this flame.Owing to the difference in the dispersion

of the prism, a slight change in the relativepositions of the spectrometer and radiom-eter was of greater consequence in the infra-red than in the visible portion of the spec-trum.The most striking characteristic of the

curve of energy distribution is the set ofelevations which are due to the emissionbands of the gases of the flame. If theacetylene is pure, the gases to be expectedare CO, and H20. According to Paschen,the maximum points of the emission bandsof these gases are as follows:

H20 Spectrum,1.46a, 1.90t, 2.83w.

CO Spectrum,2.71,u (2.68,u when CO2 is not dry) and 4.40ja.

The energy curve shows elevations whosemaxima agree very closely with thesevalutes. Observations of wave lengthslonger than 6,4 are useless, the error due tostray radiation being so great.

Similar measurements were made uponthe flame of a bunsen burner adapted forthe combustion of acetylene.

In this curve all five emission bands ap-pear and the values of the wave length atthe maximum points agree with the values

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quoted above. If we compare the bunsenand the single tip curves, we see that theydo not agree in all respects. The eleva-tions due to the emission of the 1210 gashave not the same relative values in thetwo cases, but this discrepancy disappearswhen corrections are made for slit widths.The band at 2.3p. does not appear in thebunsen flame and this fact makes its pres-ence in the other somewhat in doubt.The changes produiced in the correction

of the curves possess several points of in-terest. The maximum of intensity isshifted considerably toward the violet,appearing in the corrected curve at about0.94y.Using Langley's method of finding the

ratio of the area in the visible portion ofthe spectrum, to the area of the entire curve,the radiant efficiency was calculated. Thevalue for the cylindrical flame is 0.100 andfor the flat flame 0.131. The latter valueis not very reliable, but there is not muchdoubt but that the radiant efficiency of theflat flame is the larger. Stewart and Hoxie,using a modification of the Melloni method,found the value 0.105 for the flat flame.(To be printed in the Physical Review.)

3. ' Experiments on a New Form ofStandard High Electrical Resistance ': H.C. PARKER. (By title.)

4. ' Variation of Contact Resistance withChange of E. M. F.': H. C. PARKER.(By title.)

5. 'On Flutings in a Sound Wave and theForces due to a Flux of a Viscous Fluidaround Spheres': S. R. COOK, WashburnCollege.The author shows that the forces due to

a perfect fluid are not sufficient to producethe laminae and flutings in a sound wave,but that there are other forces which areprobably due to the viscosity of the vibrat-ing media. That there must be other forceswas first manifest by a series of experi-ments with air, carbon dioxide, chlorine and

hydrogen as media, using various materialsto foria the laminaw, including filings ofcoin silver and platinum.The autbor also shows that flutings are

not confined to a stationary sound wave butare capable of being produced by directsound waves on an open surface.A mica disk, threaded on a fine wire in a

resonanice tube, was caused to vibrate in uni-son with the prong of a large tuning fork,whose frequency was 3, per second. Koen-ig's equations for the forces due to a perfectfluid when reduced to their final form are:

X 3/27pR1RJ Joro4

z 3irpR31?3 W30ro4

M pR23 Wo sin 20.

p = density of medium, R, R,, R, are theradii of the sphere or disks, WJ' the velocityof the stream. This gives repulsion par-allel and attraction perpendicular to thestream lines. The forces were studied byfirst allowing RR, to vary while p and WJremained constant. Then p was variedwhile all other factors were kept constant,and it was shown that

Xi Z, M> PX2 ZA M2 P2

wben p, was the density of carbon dioxideand P2 that of air.A further study of the forces was made

with sealing-wax spheres and it was foundthat when the spheres, whose radii were lessthan 1 mm. were at a greater distancethan one-half their diameter apart, theyfollowed the perfect fluid forces, but whenthey were less than one-half their diameterthey were repelled perpendicular, and at-tracted parallel, to the line of flow.The author reaches the following con-

clusions:1. The conditions for the formation of

laminse are found whenever there is a fluxof a viscous fluid around solid particles.

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2. There are forces exactly opposite tothose of the perfect fluid.

3. These new forces are most probablydue to the viscosity of the medium.

4. The new forces in conj unction with theforces of a perfect fluid make possible acomplete and clear explanation of thelaminae and flutings produced in a soundwave. (To be printed in the Phil. Mag.)

6. ' Interferometer Curves : J. C. SHEDD,Colorado College.The general equation of the interference

curves is found to be a conic and the con-ditions for obtaining the various forms aredetermined by considering the question ofeccentricity.The various cases are taken up in detail

and the experimental manipulations neces-sary for obtaining them are explained.

7. 'On the Absorption Spectrum of Iodinein Solution ': EDWARD L. NICHOLs andWILLIAM W. COBLENTZ.That iodine dissolved in carbon disul-

phide, although opaque to the visible spec-trum, transmits the infra-red rays freely,has long been known, but no systematicstudies of the spectrum of such solutionsappear to have been made. In the studyof the visible spectrum a horizontal slitspectrophotometer was used. Quantitiesof iodine varying from 3.3 mg. to 0.017mg. per cubic centimeter were dissolvedand their absorption spectra measured. Asingle broad band was found, having itsmaximum at A = .52u', the transmissioncurve being steeper on the side towards theviolet. For the solution containing 0.017mg. per cc. the transmission in the centerof the band was 80 per cent. With in-creasing concentration the band widensand becomes more dense. Solutions con-taining more than .25 mg. per cc. are opaquein the center of the band, and the region ofopacity extends as the amount of iodine insolution is increased until.the entire visiblespectrum is obscured. Observations upon


iodine dissolved in alcohol showed a verydifferent absorption spectrum. Such solu-tions were opaque in the violet, the trans-mission increasing steadily towards the red.The form of the curves was such as to in-dicate an absorption band of which oneside only lies in the visible spectrum, thecenter being in the ultra-violet. To extendthese measurements to the infra-red spec-trum a Nichols. radiometer was employed.Readings of the transmission of varioussolutions were made out to 2.7p, beyondwhich wave-length the solvent itself rapidlybecomes opaque. It was found that all so-lutions rose rapidly in transmitting powerwith increasing wave-length and becamecompletely transparent between 1.0;i and1.1,x, between which region and 2.7JL, iodineappears to exert no absorbing power what-ever.

7a. 'A Preliminary Communication onthe Pressure of Light and Heat Radiation':E. F. NICHOLS and G. F. HULL.The experiment consisted of two parts:

(1) The determination of the light pressureby observing the deflection, either static orballistic, of a torsion balance when onevane of the balance was exposed to light,and (2) the determination, in ergs per sec-ond, of the intensity of the light fallingupon the vanes. The image of an aperture,upon which the rays from an arc lamp wereconcentrated by two condensing lenses, wasfocused in the plane of the glass vanesplaced symmetrically with regard to a rota-tion axis held by a quartz fiber of knowntorsion coefficient. The torsion balance wascovered by a bell jar connected to pressuregauges and a mercury pump. To eliminatethe disturbing action due to the residual gasin the receiver, the following devices wereused: (1) The vanes were silvered andhighly polished, thus making the absorp-tion small and the reflection percentagelarge. (2) The silver surface of one vanewas turned towards, and of the other, from,

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the light, thus making the effect of the gasaction and light pressure in the same di-rection on one vane, and in opposite direc-tions on the other. (3) The pressure of theair in the bell jar was varied, and thepressures were chosen in the vicinity ofthat pressure at which the gas action wasvery small. (4) The length of exposure oflight on the vane in most of the observa-tions was short. The gas action, which be-gins at zero and increases with the lengthof exposure, was thus reduced in compari-son with the instantaneous action of the ra-diation pressure. By means of an inclinedglass plate placed in front of the aperture aportion of the incident light was thrown ona thermopile. The deflection of a galva-nometer connected with the latter gave therelative light intensities.Two methods of determining radiation

pressure were used:(1) The vane was exposed continuously

to the light until the turning points of thevibration of the balance showed that staticconditions had been reached. The othervane was then exposed. Finally the wholesuspended system was turned through 1800,and the vanes were exposed in turn. Themean of the angles of deflection, multipliedby the torsion coefficient of the fiber anddivided by the lever arm, gave the force indynes acting on the vane. (2) The vaneswere exposed for a quarter of the period ofthe suspended system. The period, damp-ing coefficient, torsion coefficient and leverarm being known, the value of the radia-tion could be found. The two methodsgave practically the same result except forthe air pressures for which the gas actionwas large.The energy falling upon the vanes was

measured by means of a bolometer consist-ing of a thin disc of platinum, about thesize of the vanes, covered with platinumblack. The bolometer, occupying exactlythe position which the glass vane had pre-

viously occupied, was made one of the armsof a Wheatstone bridge. The bridge wasbalanced, the bolometer exposed to thelight, and the throw of the bridge galvanom-eter ead. Later the disc was heated by anelectric cutrrent which entered and left attwo equipoten-tial points on the bridge cur-rent and the galvanometer throw again wasread. The current strength and the resist-ance of the disc being known, the activity ofthe disc is given by iR x 10' ergs per sec-ond. The readings of the thermopile be-fore mentioned made it possible to reduce allobservations to a constant light intensity.If E= energy per second falling upon asurface, a = the percentage of the radiationreflected, v = the velocity of light, then,theoretically, the value of the radiation

(i + a)Epressure is v . The experimental

value of the pressure as found by theauthors was about 80 per cent. of the theo-retical value.

8. ' The Absorption Spectrum of FerricHydrate ': B. E. MOORE, University of Ne-braska.The author in a recent article upon ' A

Spectrophotometric Study of the Hydrolysisof Ferric Chloride,' has pointed out thatthe final product is colloid ferric hydrate.This product can be formed by Graham'sdialytic method. It would then be inferredthat identical products would have identicalabsorption spectra.

It was found that the absorption of thetwo products was quite different in charac-ter. The addition of given quantities ofchlorine or of hydrochloric acid, did noteffect any transformation in the dialyzedcolloid, i. e., crystalloids, if present, werenot changed by this treatment. If dialyzedferric hydrate, or hydrolyzed ferric chloridewere added to fresh dilute ferric chloride,the hydrolysis of the latter was accelerated.The greater acceleration was caused by thehydrolyzed ferric chloride. From this it is

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inferred that both solutions contain iden-tical colloids, but that the Graham's colloidcontains also considerable inactive crystal-loid hydrate. The absorption curve thensuggests that the crystalloid has an absorp.tion curve lying between hydrolized ferricchloride and non-hydrolized ferric chloride.(To be printed in Physical Review.)

9. ' Note on the Transmission of Radia-tion by Thin Films of Asphalt': E. L.NiCHOLS.

10. ' The Faraday Effect in Solutions ofHydrolyzed Ferric Chloride': FRED. J.BATES, University of Nebraska.The rotation of the plane of polarization

in optical transparent substances, when thelight is transmitted along the lines of mag-netic force, has been the subject of numer-ous experiments since the days of Faraday,and is known as the ' Faraday Effect.'There have been many determinations ofthe molecular rotation of substances insolution, but little effort to determinewhether the effect in solution arises from amolecule or from an ion or from both. Ob-servations have also frequently been limitedto one color (and perhaps then a mixedcolor), or to a few colors. It seemed de-sirable to extend these observations to dif-ferent parts of the spectrum. This isparticularly true of colored solutions, whosecolors correspond hypothetically to the freeperiods of their vibrations, affecting the dis-persion and probably the rotation of theplane of polarization.

Ferric chloride solutions afford a goodmeans of testing this phenomenon. Ob-servers have noted that the molecularrotation of this substance decreases upondilution of the solution. This suggests thatthe rotation arises from the moleculesrather than from the ions. The writertried a solution of sufficient concentrationto give him a rather large rotation. Thesolution was then diluted enough to leavethe effect slightly but certainly noticeable.

If the rotation was proportional to the con-centration, no effect was observed, whichsuggests that the ions are inactive or pos-sess very small rotary power in comparisonto that of the molecules. Observations byGoodwin and Moore show that dilute solu-tions of ferric chloride hydrolyze and finallyform a new produet, colloid ferric hydrate.It was thought that by restoring an ironmolecule by this process there would pos-sibly be a small rotation where previousionization had made it unobservable. Bythis test it was found that the requireddilution to obtain sufficient hydrolysismade the quantity of iron too small to giveany further evidence by the usual methodof observation. However, the use of a sun-light spectrum showed an effect as soon asone began to pass from the transparentspectral region into the absorption region.The half-shade polariscope could be readto 0.010, and in the red the difference be-tween a .01 normal solution (hydrolysisforced by heating the solution) and waterwas not more than 0.010. The differencebetween an unhydrolyzed solution of thisconcentration and water was also unob-servable. Upon/ examination of the hy-drolyzed solution at a point in the greenwhere the absorption is very marked, a ro-tation of .79° was observed, while at thesame point the other two solutions showedno difference. That is, we have here ananomalous rotary polarization or ' FaradayEffect,' analogous to anomalous dispersion.It is clear that in this case the anomalyarises from molecules in the region of theirabsorption. It remains to be seen whethersuch an anomaly will also arise in solutionwhere the absorption arises from ions.

11. ' Discharge of Electricity from Glow-ing Platinum and the Velocity of the Ions':E. RUTHERFORD.A rectangular platinum plate 14 cm.

long, 7.5 cm. wide and .002 cm. thick,was heated to incandescence by an electric

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current. The platinum plate was chargedto a known potential by means of a batteryand the current between the platinum plateand a parallel copper plate observed bymeans of a sensitive galvanometer. Therate of discharge of positive and negativeelectrification was examined under varyingconditions of temperature, distance andP. D. between the plates, and comparedwith the theoretical results deduced fromthe ionization theory of gases.At a temperature of a dull red heat posi-

tive ions are produced at surface of theplatinum plate, which travel to the oppositepl&te through the gas, if the platinum ispositively charged. The movement of theions disturbs potential gradient betweenplates and at high temperatures the slopeof potential near hot plate is extremelysmall.Let i current per sq. cm. through the gas.

n = number of ions per cc. at any point distantx from platinum plate.

VY P. D. between the plates.K- velocity of positive ion for unit potential

gradient.e= charge on ion.d distance between the plates.

Assuming the potential gradient zero atthe platinum surface, it can readily beshown that

V2K32rd3

The current is thus independent of num-ber of ions produced, i. e., the temperatureof the plate, providing it exceeds a certainvalue. Experimentally it was found:

1. For a distance of 2 cm. and under,the current at first increased rapidly withrise of temperature up to a certain point,and then more slowly. For distances offrom 3 to 8 cm. the current rose to amaximum, and then steadily decreased withrise of temperature.

2. The maximum current varied approxi-mately as square of the P. D.

3. Current diminished more rapidly than1ailThe differences observed in (1) and (3)

between experiment and theory are due to(a) decrease of velocity of ions with distancefrom heated platinum plate, (b) presence ofsome very slow-moving carriers producedat platinum surface at high temperatures.The velocity of the ions was measured

by a direct method depending on the useof an alternating P. D. of known frequency.The method was similar to that used pre-viously for determination of velocity ofions produced by ultra-violet light (Proc.Roy. Soc., 1898). It was found that thevelocity of ions was not a constant, butvaried between wide limits.This is probably due to difference in size

of ions in consequence of their varyingpower of forming clusters of moleculesround them.The following table gives results obtained

for different distances between plates. IJn-der heading ' calculated velocity I are givenvalues of K calculated from equation (1)by measuring maximum current i for givendistance and voltage.

Distance be- Velocity in cm. per sec. for 1 volt per cm.tween plates. Maximum. Average. Calculated.

2 ems. 13 7.8 5.53 "c 7.9 5.8 3.25 " - 4.7 2.2

12. 'On Conditions controlling the Dropof Potential at the Electrodes in Vacuum-Tube Discharge ': CLARENCE A. SKINNER,University of Nebraska.With the passage of electricity through

rarefied gases, it requires, relatively, a veryhigh P. D. to force the discharge directlyacross the space between the electrodeswhen these are brought within a certainsmall distance apart. To locate at whatpart of the path the potential increases wasthe primary object of this investigation.

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The results led to a more general investiga-tion of the drop of potential at the elec-trodes.A cylindrical vacuum-tube, with disk

electrodes (perpendicular to its axis) in-sulated so as to force the discharge directlyacross the space between them, and nitrogenwere used. Trhe potential of the gas at anyposition was obtained by a movable wire.As the electrodes approach each other the

drop at the anode remains constant so longas there is an extended positive column.With the anode passing through the Fara-day dark space its ' drop ' rises to a maxi-mum and then falls to zero in the negativeglow, but rises again r-apidly as the anodemoves into and through the cathode darkspace. The cathode drop remaining con-stant until the anode reaches the cathodedark space begins then to increase withgreat rapidity. During these changes theconductivity of the gas does not vary.These results are explained on the hy-

pothesis that the impact velocity of thedischarging ion tends to prevent chargefrom being transmitted to the electrode;that to give up its charge the ion mustfirst come to rest.

Other Observations.-At the cathode thedrop may be expressed by the equation

V-C+ (a+i)

where i is the current density; p, the gaspressure; C, a constant approximating invalue the cathode drop, as measured byWarburg; c, a constant depending on thenature of the gas, but independent of themetal used as cathode; and a, a constant.At the anode the drop appears to vary ac-cording to a similar law, where c is aboutone thirty-fifth its magnitude at the ca-thode.The great difference in magnitude of the

drops at the two electrodes may be ex-plained on the hypothesis that the positiveion is of much greater mass than the nega-

tive and hence (for the same impact veloc-ity), its elastic reaction being greater, thegreater resistance to its discharge.The difference in the drop occasioned by

the use of different metals may be ex-plained by their contact-potentials. Of twometals, that possessing the greater attracstion for negative electricity is found to pos-sess the lower drop as anode, apparently byits attraction for the charge on the ion aid,ing in overcoming the elastic reaction ofthe impinging ion. The same applies tothe cathode. (To be printed in the Phil.Mag.)

13. ' The Influence of Temperature uponthe Photo-electric Effect' JOHN ZELENY,University of Minnesota.

Ultra-violet light impinging upon naega-tively electrified bodies dissipates theircharge. The electricity is supposed to becarried away by ions which are formed atthe surface of the body by the rapid ab-sorption of certain of the waves of the in-cident light. A study of the influence oftemperature upon the effect was made tosee if it would throw any light upon thequestion as to the relative parts played inthe phenomenon by the material of thebody and by the occluded gases. Thecharged body which was experimented uponwas a platinum wire that could be heatedby sending an electric current through it.The light used was obtained from an elec-tric spark produced between two zinc rodsby an induiction coil. The results obtainedare somewhat complicated. As the tem-perature was gradually increased to about2000 C., it was found that the rate at whichthe negative electricity was discharged di-minished. but for still higher temperaturesit increased again, so that at about 7000 C.,it was nearly three times its value at roomtemperature. The rate of discharge at cer-tain temperatures depends considerablyupon the immediate previous history of thewire, being much larger for a given temper-

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ature, although diminishing with time, ifthe wire has just been hotter than if it hasjuist been colder. The conditions at thesurface of the body at these temperaturesreach their steady state but slowly, whilefor temperatures below 1000 C. this is ac-quired much more rapidly. Changes in themolecular arrangement of the body, as wellas the amount oft he occluded gas, mayplay a large part in the phenomenon.From an iron wire the rate of dischargewhile small at the lower temperatures be-came many times larger at the higher tem-peratures. It was also found that a posi-tively charged body does not lose anycharge due to the action of the light, evenwhen its temperature is raised to that ofred heat. To get an explanation for theunipolarity of the photo-electric effect, weneed but consider that the intra-molecularimpulses which are produced by the light,and which give rise to the discharge, areable to throw off from the body the nega-tive ions or corpuscles, but are not able todisengage the much larger positive ions forwhich the forces of restitution are corre-spondingly greater.

14. ' The Diminution of the PotentialDifference between the Electrodes of aVacuum Tube produced by a MagneticField : JOHN E. ALMY.

15. ' Note on the Discharge Current froma Surface of Large Curvature': JOHN E.ALMY, University of Nebraska.The discharge from a wire to a surround-

ing concentric cylinder, with reference todischarge current, especially, is studied.The law of discharge, under the conditionsgiven below is found, I=aV(V- b)L/R',where

I= the discharge current, passing from wire tocylinder.V- the potential difference between wire and cyl-

inder.L = the length of the wire.R= the radius of the cylinder.

b -a constant, with given apparatus and gaspressure, and is very approximately the 'minimumpotential ' of Rontgen.a- a constant.

The applicability to the discharge wasshown with gas pressures, from 20 to 75 cm.of mercury, with cylinders, up to 10 cm. indiameter. The proportionality of currentto wire length holds so long as the wirelength is greater than the radius of the cyl-inder used. Finally, the proportionalityof current to the inverse cube of the cylin-der radius does not hold accurately. More

strictlv speaking it may be said that I cc I

and 3.3 > n > 2.8, in the experimentsmade.

16. ' The Radiant Efficiency of VicuumTubes ': E. E. ROBERTS.

17. 'On the Spark Discharge duringRapid Oscillations': K. E. GUTHE. (Bytitle.)

18. 'Results of Recent Magnetic Workof the U. S. Coast and Geodetic Survey ':L. A. BAUER. (By title.)

19. ' The Physical Decomposition of theEarth's Permanent Magnetic Field ': L. A.BAUER. (By title.)

20. 'On the Calorimetric Properties ofthe Ferro-magnetic Substances, with specialreference to Nickel-steel ': B. V. HILL.

It is well known that the ferro-magneticsubstances when heated through a certainrange of temperature, depending on the na-ture of the substance, absorb latent heatand pass into an allotropic modification inwhich they are non-magnetic. Certain al-loys (e. g., nickel-steel) having been trans-formed into this state by heating, nmaintainit down to comparatively low temperatures,so that there are many so-called irreversiblenickel-steel alloys to be obtained in bothmodifications within the same range of tem-perature (200 to 3000 C.). This allows theproperties of the alloys in the two states tobe compared.

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The latent heat of transformation for onesample of nickel-steel was found to be 2.783;that of another, 13.45; which, according tothe theory of solutions, should have been15.9-the application of the theory being,however, questionable. The specific heatof nickel-steel is greater in the non-magneticstate than in the magnetic (from 2 to 6 percent., depending on the temnperature intervalthrough which it is obtained).

Six samples of iron differing in permea-bility showed that the greater the permea-bility of iron the smaller its specific heat.This supports the view that the differencein permeability is caused by a difference incomposition of magnetic and non-magneticiron.

21. "On the Demagnetizing Effect of aDischarge in Iron when Electromagnet-ically Compensated': ZENO CROOK.

22. 'The Absorption Spectra of Solutionsof Potassium Permanganate ': B. E. MOORE,University of Nebraska.

Tlih absorption spectra of soltutions ofthe following concentrations, .25n, .025n,.0025n,.00025n and. 000025nt (n = normal),were studied.The observations, though they may need

later sdme slight correction, show that upondilution the solutions become relativelydarker in the blue, i. e., there is a displace-ment of the absorption band toward theblue upon dilution. The phenomenon is ex-plained upon the theory of dissociation.

23. ' The Absorption and Dispersion ofFuchsin ': W. B. CARTMEL. (By title.)

24. ' On the Determination of Dispersionby Means of Channeled Spectra with theConcave Grating ': P. J. ANTES.

25. 'Accidental Double Refraction inLiquids ': BRUCE V. HILL, University ofNebraska.

In a former paper upon this subject(Phil. Mag. (5), 48, p. 485) the writergave results of a series of experiments upongelatinizing solutions which became double

refracting when subjected to a strain be-tween rotating cylinders. The results in-dicated that we have in such solutions quasi-solids, and that there is a difference betweencolloid and crystalloid solutions not to beexplained upon the assumption of a largemolecular weight in the former.The present experiments consist of an

examination of water solutions of gelatinewhen subjected to a static stra'in. Theyvary in concentration from .1 per cent. to .5per cent. and were too dilute to sustain theirown weight. They were accordinglv placedin thin-walled brass tubes 42.55 cm. inlength and 2.77 cm. in diameter. Glasscaps were fastened to the ends of thesetubes by slipping short pieces of rubberhose over them. The tubes were strained,so that their cross-sections were elliptical,by means of clamps. The double refractiondecreases so rapidly with rise in tempera-ture that at room temperature--about 230C.-no effect was visible in jellies of theabove concentrations. The tubes werethen surrounded by ice and the formationof dew upon the glass ends was obviatedby slipping over the tube a second one, alsohaving a glass cap and containing a littlephosphoric anhydride. The amount ofdouble refraction was measured as beforeby means of a half-shade polariscope. Theseven sets of observations show that whena stress is applied, the strain increases to acertain point beyond which no furtherstrain is produced. Further stress rupturesthe solution, and the refraction diminishesor ceases. The amount a solution can bestrained without rupturing depends uponthe age of the solution. This point wassufficiently studied to show that the diluterjellies required much longer time to reachthe point where they would sustain a max-imum strain than the stronger jellies.Along with double refraction, depolariza-tion also appears and then diminishes afterstanding some time.

594 SCIEzNCE.

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OCTOBER 18, 1901. ]

These solutions are as fluid as water,but still behave optically as quasi-solids,capable of sustaining a static strain withouta displacement of the mobile particles.This condition is reached very slowly andthe depolarization early in the formationindicates that the progress of formation ofthe solid structure is not homogeneous, butthat it later becomes so, as indicated by thedisappearance of the depolarization.

26. ' Notes on Dielectric Strain': LouisTRENCHARD MORE, University of Cincinnati.

This paper-' Notes on Dielectric Strain-is an answer to a paper by Dr. Paul Sacer-dote (Philosophical M/lagazine, March, 1901),criticizing an article by me which appearedin the Philosophical Magazine for August,1900. In attempting to extend the workof Quincke and others who found thatglass, when electrified, elongated propor-tionally to the square of the difference ofpotential and inversely as the square ofthe thickness of the dielectric, I noticedthat after errors were eliminated the effect

vanished or was at least less than =10-13

-a result much less than that found byformer investigators. My work attractedthe attention of Professor Cantone and Dr.Sacerdote, the latter of whom had recentlypublished a theoretical discussion of thesubject. This theory is based on a coeffi-cient which expresses the relation betweenthe potential and the elongation and sofails if the elongation is eliminated. Dr.Sacerdote's criticism showed, I thought,that he had not understood my results andhad underestimated the delicacy of myapparatus which seems fully capable of re-cording the changes of length noticed bythe most accurate of former investigators-Professor Cantone.

I have in these papers shown that myappara.tus was capable of measuring theeffect-that it did record an effect similarto that noted by other investigators, but

that this effect was due to bending of theglass tube by electrostatic attraction-thatthis error being eliminated the effect van-ished.The sources of errors of former investi-

gators are probably the following:1. No adequate precautions were taken

against lateral bending of the tube. Thechanges of length produiced by an extremelysmall deflection would account for the en-tire amount of the effect.

2. The elongations are too close to limitof observation to establish a law when theeffect itself is still questionable.

3. Changes of length on charge and dis-charge are not equal. This difference some-times equals 40 per cent. of the entire change.An extraneous effect of such magnitudecasts doubt on the cause of the elongation.

4. With each investigator, using im-proved and more delicate apparatus, theamount of the effect steadily decreases.This points either to a partial or entireinfluence of extraneous causes. (To beprinted in the Philosophical Magazine.)

27. 'The Temperature Gradient of theAtmosphere, with Formula': S. R. COOK,Washburn College.The author calls attention to the diffi-

culty, in discussing the escape of gases fi omthe atmosphere, of determining the tem-perature of the station in the upper atmos-phere under consideration.From the kite observations of the United

States Weather Bureau and the recent bal-loon ascensions at Paris, it was shown thatthe rate of decrease of temperature withaltitude was not constant.From balloon ascensions made March 24,

1899, near Paris an experimental formu'at toe-72 was obtained for the temperaturegradient when t, and t0 are the absolutetemperatures at positions whose distancesfrom the surface are x, and at the surfacerespectively, and when k is a constant ob-tained from the balloon ascensions.

SCIENCE. 595

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SCIENCE.

The graph of the temperature gradientis given alnd compared with Ferrel's graph.A density graph computed from the pres-sure and temperature graphs is also givenand compared with Cottier's density graph

computed from the formula?o°- Po )vwhereP1 P1

v has the experimental value 1.2.Attention is also called to the need of

more accurate and systematic data for thedetermination of the temperature gradientat altitudes from 5,000 to 20,000 meters.

JOHN ZELENY,Secretary.

THE AMERICAN ASSOCIATION FOR THE AD-VANCEMENT OF SCIENCE.

SECTION G, BOTANY.THE Section met for organization on Mon-

day, August 26, at 11.30 a. i., with theVice-President, Mr. B. T. Galloway, in thechair. The following were the officers forthe Denver meeting:

Vice-President, B. T. Galloway.Secretary, E. A. Bessey (in absence of A. S. Hitch-

cock).Sectional Committee, Wm. Trelease, Vice-President

1900; D. T. MacDougal, Secretary 1900; B. T.Galloway, Vice-President 1901; E. A. Bessey, Secre-tary 1901; C. E. Bessevy C. L. Shear, Miss C. E.Cummings.Member of General Committee, W. J. Beal.Member of Council, D. H. Campbell and L. M.

Underwood.*On Wednesday, August 28, in accord-

ance with the custom established at thelast New York meeting, Section G held ajoint session with the Botanical Society ofAmerica, the officers of the latter takingcharge of the meeting.On Thursday evening the following were

chosen by the General Committee as Vice-President and Secretary, respectively, forthe Pittsburg meeting, June, 1902: D. H.Campbell, Leland Stanford University, andHermann von Schrenk, Shaw School ofBotany.* Chosen to succeed D. H. Campbell after the

latter's early departure.

The following is a complete list of thepapers presented. Abstracts are givenwhere furnished by the authors, except forthe papers presented at the joint meetingwith the Botanical Society of America, ab-stracts of which will be published elsewhereby the Secretary of that Society.

1. ' Thermal Relations of Plants': D.T.. MAcDOUGAL. (No abstract furnished.)

2. ' Experiments with Lime and Solu-tions of Formaldehyde in the Prevention ofOnion Smut ': A. D. SELBY.Onion Smut, Urocystis cepulce Frost, a soil-

infesting fungus, bas become introduced intosoils devoted to the growing of onion setsnear Chillicothe, Ohio, and into those de-voted to the growing of market onions aboutBerea, Ohio. Certain results of experi-ments made in 1900 at Chillicothe werepublished in a bulletin (No. 122) of theOhio Experiment Station. These showeddecided advantages of quicklime applied tothe soil before seeding and of dilute solu-tions of formaldehyde in water sprinkledupon the seeds in contact with the soil, ascompared with flowers of sulphur, suilphurand lime (in small quantities), and othersubstances heretofore proposed for the pre-vention of onion smut. More extended ex-periments along these lines were conductedboth at Chillicothe and Berea during 1901.The results from Chillicothe are now athand and show very gratifying smut pre-vention and corresponding increase in theyield of onion sets. All plots herein con-sidered are 760 square feet in area; resultsare stated in actual and calculated yields.Plot. Treatment. Actual yield, Calculated yield

lbs. per plot. per acre, bushels.I. Lime, 34 bu. per A. 121.6 174.II. " 70 " " " 152.0 217.5

III. Formalin, .375% sol. 196.0 280.8IV. Nothing 92. (large sets) 131.8V. Formalin, .75% sol. 202. 289.4

VI. Lime, 125 bu. per A. 203. 290.8VII. " 70 " " "

and Formalin, .375%sol. 214. 306.5

596 [N. S. VOL. XIV. No. 355

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SECTION B, PHYSICSJOHN ZELENY

DOI: 10.1126/science.14.355.585 (355), 585-596.14Science

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Association for the Advancement of Science. No claim to original U.S. Government Works.Copyright © 1901 The Authors, some rights reserved; exclusive licensee American

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SCIENCE · OCTOBER 18, 1901.] quoted above. If wecompare the bunsen andthe single tip curves, wesee that they do not agree in all respects. The eleva-tions due to the emission of