will provide a scientific link between growers and manufacturers.

THE Bureau of Chemistry, U. S. Department of Agriculture, is now prepared to supply standard substances that conform to the biologic assay requirements of the Tenth U. S. Pharmacopeia, according to the Journal of the American Medical Association. Manufacturers are invited to apply, indicating the amount of material they desire against which to check their biologic assays. The new Pharmacopeia will state in the preface that biologic assays have now been made compulsory for a number of important drugs and preparations, and to facilitate the adoption of these standards and to provide a greater degree of uniformity in the application of these assays, the officials of the Bureau of Chemistry have indicated their willingness to supply substances conforming to the new standards. This service is the result of cooperation between the committee of revision, the manufacturers and the Bureau of Chemistry.

THE Journal of the American Medical Association writes that the degree of bachelor of science in hygiene will not be given after this year at the Johns Hopkins School of Hygiene and Public Health. The elimination of this degree will make the institution virtually a graduate school. Although conforming to the policy announced by the university last winter, Dr. William H. Howell, assistant director, said the step was taken largely to meet conditions outside rather than to follow the general scheme proposed by the president. This is the third step in the return of Johns Hopkins to its original standard as a graduate institution, the previous ones having been the proposal at Homewood to drop the first two years of college work and with them the A.B. degree (practically eliminating the College of Arts and Sciences), and the decision of the medical school to admit only those highly prepared. The degree of bachelor of science in hygiene was originally to train public health workers. Student candidates with two years of college work were instructed in special subjects for two years more at the School of Hygiene and Public Health, making the course four years in all. There have been a limited number of openings for the bachelors of science in hygiene, and therefore an increasingly smaller number of candidates for the degree. The new School of Hygiene will move into its new building in the hospital group about October 1. The celebration will be delayed until 1926, when the university observes its fiftieth anniversary.

Nature writes, "The German Chemical Society has recently published a 'warning' directing attention to the very large numbers of young chemists now com

ing from the universities, many of whom are unable to find suitable employment. Figures are given showing the extraordinary increase in graduates from the chemical faculty, as compared with those from other departments of the universities. It is anticipated that the number of chemical graduates this year will be about 1,100, whereas it is computed that German industry is only able to absorb about one third of that number, that is to say, about 350 per annum. Opportunities abroad for German chemists are now considerably less than they were before the war, partly for political or sentimental reasons, and partly because of the growing tendency in most countries having industrial aspirations to develop their chemical industry by employing their own chemists to the almost total exclusion of the foreigner."

UNIVERSITY AND EDUCATIONAL
NOTES

THE greater part of the estate amounting to $2,300,000 of the late Edward Rector, the attorney of Chicago, is bequeathed to De Pauw University, at Greencastle, Ind., of which he was a trustee. Annual scholarships at De Pauw for every high school in Indiana were included in the bequest. At the time of his death, five hundred of its eighteen hundred students were being educated at the expense of Mr. Rector. The will provides for the addition of $100,000 for the retiring allowance of faculty and administration members, and for two dormitories, one for men and one for women, each to cost $250,000. About $1,700,000 is to be added to the Edward Rector scholarship fund, founded in 1918, with an endowment of $1,000,000. One of his benefactions is a fund, placed at the disposal of the university authorities, whereby money may be loaned to Rector scholars for living expenses. These loans may be repaid after graduation.

WITH $7,000,000 raised of the total of $10,000,000 necessary for the erection of the 52-story "Cathedral of Learning" of the University of Pittsburgh, the university trustees have appointed a building committee which is making preliminary surveys on the site. It is expected that ground will be broken in October, and that the remainder of the cost will be obtained in the near future. The university stadium, which has just been completed at a cost of $2,100,000, is being used for university athletic contests this fall. Its seating capacity is 70,000.

THE Johns Hopkins School of Hygiene and Public Health moved from its old site on West Monument Street to its new building at East Monument and Wolfe Streets on August 13.

SIR RICKMAN GODLEE, the well-known surgeon, who died on April 20 at the age of seventy-six years, left subject to a life interest for his wife the residue of his estate to University College, London, and to University College Hospital. The gross value of the estate is £94,148. Among special bequests is £10,000 to endow scholarships for students of the University College Hospital Medical School.

PROFESSOR HENRY T. MOORE, professor of psychology at Dartmouth College, who recently was elected to a professorship in the University of Michigan, has been elected president of Skidmore College, vacant through the death of the late Charles H. Keyes.

ALBERT BRITT, of the Frank A. Munsey Publishing Company of New York City, previously for fourteen years editor of Outing, has been elected to the presidency of Knox College, of which he is an alumnus, to succeed Dr. James L. McConaughy, who was recently inaugurated as president of Wesleyan University.

THE American University, at Washington, D. C., which has long existed as only a graduate school, and which during the war gave over its campus and buildings to government use, has again resumed control of the campus and will this autumn open a college of liberal arts, with Dr. Geo. B. Woods as dean; Dr. J. W. Hornbeck, recently of Carleton College, has been appointed professor of physics; Mr. F. A. Varrelman, recently biologist to the National Research Council Marine Investigations and special assistant of the Bureau of Fisheries, as assistant professor of biology, and Dr. E. W. Gurnsey, of the Fixed Nitrogen Laboratories of the Department of Agriculture, instructor of chemistry.

DR. ERNEST C. LEVY, formerly director of public welfare for the city of Richmond, Va., has been appointed professor of preventive medicine in the medical college of the University of Virginia.

DR. ARCHIE GARFIELD WORTHING, of the Nela Research Laboratory, Cleveland, Ohio, has been appointed professor and head of the department of physics of the University of Pittsburgh, succeeding Dr. Lee Paul Sieg, who has been made dean of the college and graduate school.

DR. ELMER O. KRAEMER, national research fellow in colloid chemistry, has been appointed assistant professor to conduct research and give instruction in colloid chemistry at the University of Wisconsin.

DR. VICTOR F. HESS, associate professor of experimental physics in the University of Graz (Austria), has been promoted to a full professorship. Professor

Hess was director of the research laboratory of the U. S. Radium Corporation, New York, 1921 to 1923 and also consulting physicist to the U. S. Bureau of Mines.

J. S. HUXLEY, fellow of New College, Oxford, and senior demonstrator in the department of comparative anatomy, has been appointed to the university chair of zoology tenable at King's College.

DISCUSSION AND CORRESPONDENCE EVOLUTION IN THE PHYSICAL WORLD

one.

IN a recent number of SCIENCE (July 17) Professor Henry Fairfield Osborn states that "in chemistry and physics the evolution of the chemical elements has recently been demonstrated." What does Professor Osborn mean? Probably this, that we have rather recently learned that there are units or entities called electrons which help to form the atoms of all elements, and perhaps that there are other units or entities which some scientists have called protons which may also be constituents of all atoms so that we now picture the atoms of different elements as differing only in the number and arrangement and motions of these two kinds of entities. Probably also Professor Osborn has in mind the phenomenon of radioactivity which is exemplified chiefly by radium in which we see transformations going on and by means of which a complex atom breaks down and changes over into a simpler But are we justified in saying that we have demonstrated the evolution of the chemical elements? Certainly not in the sense in which that word is ordinarily used. Some of the changes taking place in radioactivity occur in minute fractions of time, others require ages, but all are associated with degeneration or changing from complex to simpler forms of matter. We have no evidence whatever for the opposite process, the building up from simple to complex and we have no evidence whatever that the atoms of chemical elements have by slow accretions acquired their present structure and characteristics. Does any physicist hold the view that electrons have come into existence only in recent times or that they gradually have selected partners and with these partners arranged themselves in groups to form our atoms of to-day? Perhaps so, but no physicist is giving much time to such speculation, for the vastly more important matter is to find out what is happening in the physical universe to-day. We can have no knowledge of the past except as we obtain it from our knowledge of the universe of the present.

And this brings me to emphasize one point which is not stressed in texts or courses on evolution. There are evidences everywhere that changes have taken place in the organic world, but to account for those

ན

changes we assume that the modes in which nature operates now have not changed that the laws of nature by which these changes have been brought about are unchanging. If we do not make this assumption, if we assume on the other hand that the laws of nature or the modes in which we see nature now operating are themselves subject to change or are themselves undergoing evolution, then we must know the manner of change or the law of change of the laws—either that or we must be free to postulate any law of change O that we please, in which case we can build up any theory of evolution that suits us.

For example, has matter recently acquired the property of attracting to itself other matter, has an electric charge gradually taken on the power of attracting or repelling other charges, has energy recently acquired its characteristics? Or did Newton when he stated the law of gravitation state a property of matter, which, so far as this little mind of ours can picture the universe of time and space, holds forever and forever? We may find that Newton's statement was incomplete, but such a discovery, if made, will not point to evolution in gravitation but to evolution in our comprehension of the phenomenon. So we come to view our universe as one of constant change subject to unchanging law. In physics we are dealing with the eternal verities.

Another view which is ordinarily not presented in discussions on evolution is that our universe is like a clock which having been wound up is now running down. For it is a clearly established law in physics that when transformations of energy take place-and they are always taking place-energy, though conserved, becomes unavailable. Thus in accounting for our universe we must start with it already wound up -filled with a vast quantity of high-grade energythen with a suitable hypothesis, we may acquiesce in the nebular theory according to Laplace or the planetesimal according to Chamberlain or the spirally nebular according to Jeans and thus we may account for the so-called growth of worlds. It is true that going

back only a few hundred million years we can joggle along comfortably, flinging off spiral nebulae here and there, on the way down. But we don't care to be questioned too closely regarding events before that time. I think that the opponents of evolution are justified in saying that we do not know what happened long ago, but while they would mean by that term a few thousand we would mean many million years.

The idea that there has been evolution in the physical world is not new. Many philosophers have proposed it. The clearest enunciation probably was given by Descartes three hundred years ago "the physical world and all things in it whether living or dead have originated out of primitive formless matter by a pro

cess of evolution due to the continuous operation of physical laws." But at that time practically nothing was known about physical laws. Not even the law of gravitation was known; nothing was known about electricity or light. Yet vast ignorance of all nature's operations did not prevent Descartes from propounding his broad philosophy. Philosophers are not disturbed by ignorance of facts, but scientists have no other basis for their generalizations.

The teachers of evolution are, I am afraid, apt to extend the meaning of the word beyond the original and to see evolution in the illumination produced by the striking of a match. This phenomenon is not unlike that associated with the so-called birth of a star. But if we want to know what happens when a match is struck or a star is born we must study physics and chemistry not evolution.

DARTMOUTH COLLEGE

G. F. HULL

NOTE ON THE SEPARATION OF THE
DEPRESSOR PRINCIPLE FROM
HEPATIC TISSUE

THE action of water soluble substances prepared from hepatic tissue in lowering the blood pressure of normal animals has been noted in the literature many years previous. Investigations as to the chemical nature of this principle which were initiated in this laboratory and the department of physiology eighteen months ago by Drs. James and Laughton have yielded the following results.

The active principle is non-protein in character and is found in the abiuret fraction. It is soluble in water alcohol solutions up to 80 per cent. strength. It is precipitated from aqueous solutions by phosphotungstic acid along with the diamino acid fraction, and the material recovered in aqueous solution can be further purified by extraction with ether, which has the capacity for dissolving out a very active principle which depresses the arterial tension and maintains it at sub-normal levels for long periods.

The depressor substance is associated with a pressor principle in the abiuret fraction. These two are separated during the treatment with phosphotungstic acid, since practically all the pressor element remains in solution.

Not only is the normal pressure reduced to subnormal levels, but artificial hypertension induced by various well-known pressor substances is similarly reduced to any desired level depending on the dose employed.

A. A. JAMES

N. B. LAUGHTON
A. BRUCE MACALLUM

UNIVERSITY OF WESTERN ONTARIO

THE EFFECT OF NOISE ON HEARING REFERRING to the effect of noise on hearing, Correspondent "B" in SCIENCE of March 6, 1925, page 260, proposed a theory which, to use his, words, "seemed reasonable." For his information, and for the information of others who have been interested in the discussion, I shall present a couple of cases in which "a more or less regular succession" of vibrations is employed to jar a mechanism having a vibration of its own, to a state of higher sensitivity.

The power delivered by a steam turbine is governed by a valve controlling the admission of steam to the turbine. If the demand made upon the turbine must be continually varied in accordance with varying conditions of the system of which the turbine is a part, the movable part of the valve must function quickly and smoothly, in order to supply the turbine with the proper amount of steam at any instant. This part has therefore been made to move, in many such turbines, with a continuous oscillatory motion, at all times. In this way the response is quickened and sticking avoided. The actual or total motion consists of a sort of high frequency wave of small amplitude superposed upon an irregular wave of greater amplitude. The amount of steam admitted is practically the same as if only the larger wave were followed, but it is found that the auxiliary agitation augments the sensitivity.

The second example of the application of the same principle is connected with my own work.

Signals from ocean cables are ordinarily recorded by means of a "siphon recorder" upon a moving paper tape. The incoming impulses are weak, and the friction of the "pen," or siphon, upon the paper, is comparatively great. Consequently an arrangement is provided whereby .the siphon can be kept constantly agitated with infinitesimal vibrations. The friction is thus considerably reduced, and the sensitivity increased. Greatest sensitivity is obtained when the direction of the vibrations is perpendicular to the plane of the paper.

JOHN W. ARNOLD WESTERN UNION TELEGRAPH COMPANY, NEW YORK, N. Y.

A LUMINOUS SPIDER

ONE day in Central Burma the trail in the jungle was exceptionally difficult. It was long past noon when I realized that the return journey would be equally long and tiring.

Camp lay on the other side of a long range of hills and there was a short cut from the main trail that would save several miles, but this trail was faint. I reached the supposed cut-off about dusk and fol

lowed it upward. Darkness came on swiftly and my pony began to stumble. Somewhere we had missed the trail, for at intervals. I could still glimpse the crest of the hills and I knew my general direction.

Fireflies sparkled here and there. Presently a few feet away I saw a ball of light as large as one's thumb. It was stationary. Tying the horse, I approached it as carefully as possible, finding it surrounded by thorny bushes. It did not move and I pressed the brush aside until I was directly over it and then struck a match. There in full view was a spider, his large oval abdomen grayish, with darker markings. Still he did not move, and as the match died out his abdomen again glowed to full power, a completely oval light, similar in quality to that of the fireflies. Remembering native tales of poisonous insects, I wrapped a handkerchief around one hand, parted the brush with the other, and when close enough made a quick grab. Alas! The handkerchief caught on a stick before I could encircle him and my treasure scurried away. I followed as quickly as possible, but the light soon disappeared under stones, brush or in some burrow, for I never saw it again.

Many nights I searched in the jungle and questioned natives and white officers who had passed through that district, but apparently no one else had reported a luminous spider, nor can I find record of any known elsewhere.

Burmese never leave their houses after dark on account of their fear of spirits, so it is not surprising that the natives had never seen one, but some other traveler may be so fortunate as to capture one of these spiders.

The place where I saw the specimen was between the villages of Kyawdaw and Thitkydaing, Pakkoku District, about one hundred and twenty miles west of Mandalay, Burma, in April, 1923.

BARNUM BROWN AMERICAN MUSEUM OF NATURAL HISTORY

di

values of in the vicinity of a maximum are obtained dv

as a small difference of two large numbers.

Dymond2 has devised a method for recording directly and precisely a curve which is practically di identical with that of plotted against voltage. A dv

small alternating potential Av is superposed on the potential v by means of a commutator. During one half revolution of the commutator the current has the value i+ Ai; during the other half, it is i- Ai. The current is now passed through a second commutator rotating on the same shaft as the first. The commuted current is i + Ai during the first half-cycle and

iAi during the second. Thus, it is equivalent to an alternating current i superposed on a steady current Ai, and gives deflections proportional to Ai on a long-period galvanometer. Dymond suggests that a transformer or a bridge could be used to suppress the current i before the commutation, but in practice he found that this current was not large enough to injure his galvanometer and that it did. not affect his readings.

This note describes a method for recording directly d2i the curve- Of course, the zeros of this curve give dy2

In addition to its applications to critical potential problems, which are limited only by the inconstancy of the currents to be measured, it is thought that this method may prove valuable in studying the characteristics of thermionic devices, where detecting ability d2i depends essentially on dy2.

BUREAU OF STANDARDS

ARTHUR EDWARD RUARK

SPECIAL ARTICLES

THEORY OF THE PROPAGATION OF SHORT RADIO WAVES OVER LONG DISTANCES RECENT experiments by Taylor, to be published shortly, on the transmission of radio waves of wavelength from 3,000 to 16 meters over distances up to 10,000 miles, have brought to light new facts. Those of particular interest in the present preliminary note concern themselves with the change in the intensity of the received signal with the distance from the transmitter. It has been found that for wave-lengths shorter than 50 meters the received intensity decreased as the distance from the transmitter was increased, reaching a value too small to be observed at a disrance of a hundred miles or so. With further inerease of distance the received signal remained undetectable until a point was reached where the received signal became strong again, rising rapidly to a maximum and thereafter decreasing rather slowly. The length of the region of silence, which we may call the "skip distance," was found to increase rapidly as the wave-length decreased, being roughly 400 miles for wave-length 32 meters and 1,300 miles for 16 meters, for daylight transmission and specified conditions of transmission and reception.

In a simple theoretical explanation of these facts we distinguish two portions of the wave propagated from the transmitting antenna, one of which clings to the surface of the earth and decreases rapidly in intensity with the distance until it is lost, and the other which moves in an upward direction and ex·periences reflection from the Heaviside layer. This layer is assumed to be a dispersive medium with a critical frequency corresponding to a wave-length between 100 and 200 meters. This critical frequency results from the motions of the electrons in the earth's magnetic field as suggested by Appleton and by Nichols and Schelling. When plane polarized radiation with electric vector in the plane of incidence is reflected from such a medium into air anomalies will occur at the Brewster and Snell angles, the reflected intensity being zero at the Brewster angle and 100 per cent. at the Snell angle. It is assumed that the portion of the wave propagated upward is