regular opportunities of graduate students and investigators, but also to the farming interests of the state, to whom the combined efforts and results are valuable. The affiliation, thus bringing a mutual extension of privileges, is characterized by the authorities as a gain to both institutions without cost or loss to either."

SCIENTIFIC NOTES AND NEWS THE next meeting of the American Astronomical Society will be held at Smith College Observatory, Northampton, Massachusetts, beginning on September 1. The society will also visit the observatory at Mt. Holyoke College.

THE American Association of Anatomists will hold their annual meeting at the National Museum, Washington, D. C., from April 1 to 3. The program contains about sixty titles for papers and fifty demonstrations.

THE second annual meeting of the American Society of Mammalogists will be held in the American Museum of Natural History, New York City, May 3-5, 1920. There will be opportunities to visit the New York Zoological Park, the Brooklyn Museum, the New York Aquarium, and other institutions of interest to members. Headquarters will be at the Hotel York, 7th Avenue and 36th Street, three blocks north of the Pennsylvania Station.

DR. JOHN CHARLES HESSLER has been appointed assistant director of the Mellon Institute of Industrial Research of the University of Pittsburgh. Dr. Hessler, who is now serving as president of James Milliken University, Decatur, Ill., will enter upon his new work at the close of the present academic year. As a member of the administrative staff of the Mellon Institute, he will be in supervisory charge of certain of the researches in organic chemistry, a field in which he has specialized during the past twenty years.

DR. JOHN W. MACFARLANE, professor of botany and director of the Botanical Laboratory and of the Botanic Gardens of the University of Pennsylvania, has tendered his

resignation after twenty-eight years of service, to take effect on June 30.

DR. WALDEMAR T. SCHALLER has resigned as chemist in the division of physical and chemical research, United States Geological Survey, and has accepted a position with the Great Southern Sulphur Co., Inc., of New Orleans, La., operating at Orla, Texas.

THE French government has conferred the decoration, "Officier de l'Instruction Publique," upon Professor E. B. Van Vleck, of the department of mathematics of the University of Wisconsin, in recognition of his services as teacher and investigator and for his work during the war.

PROFESSOR WARREN H. LEWIS, of the Johns Hopkins Medical School, has been elected an honorary member of the Society of Medicine of Gand.

AT its meeting held on March 10, the Rumford Committee of the American Academy of Arts and Sciences appropriated the sum of $250 to Professor Julius Stieglitz in aid of the publication of Marie's "Tables of Constants."

AT a meeting of the Royal Society of the Medical and Natural Sciences of Brussels held on December 1, Dr. John J. Abel, professor of pharmacology at the Johns Hopkins University, was elected an associate member of the society.

THE Committee on Scientific Research of the American Medical Association has made these grants for scientific work: Professor G. Carl Huber, University of Michigan, for study of nerve repair, $400. Professor H. M. Evans, University of California, for study of the influence of endocrine glands on ovulation, $400. Professor E. R. LeCount, Rush Medical College, for study of extradural hemorrhage and of the hydrogen-ion content of the blood in experimental streptococcus infections, $200. Dr. E. E. Ecker, Western Reserve University, for a study of the specificness of antianaphylaxis, $200. Dr. Henrietta Calhoun, Iowa, State University, for a study of the effect of protein shock on diphtheria intoxication, $400.

THE Council of the Royal Society has recommended the following: Dr. Edward Frankland Armstrong, Sir Jagadis Chunder Bose, Dr. Robert Broom, Professor Edward Provan Cathcart, Mr. Alfred Chaston Chapman, Dr. Arthur Price Chattock, Mr. Arthur William Hill, Dr. Cargill Gilston Knott, Professor Frederick Alexander Lindemann, Dr. Francis Hugh Adam Marshall, Dr. Thomas Ralph Merton, Dr. Robert Cyril Layton Perkins, Professor Henry Crozier Plummer, Professor Robert Robinson, and Professor John William Watson Stephens.

AT the annual meeting of the Optical Society, London, Mr. R. S. Whipple was elected to the presidency; the vice-presidents are: Professor F. J. Cheshire, Sir Herbert Jackson, and Mr. H. F. Purser.

DR. E. P. WIGHTMAN, recently of Parke Davis and Co., of Detroit, has accepted a position as research chemist with the Eastman Kodak Co., Rochester, N. Y.

LIEUTENANT SCHACHNE ISAACS, formerly instructor in psychology at the University of Cincinnati, and at present psychologist in the Air Service, Medical Research Laboratory, Mitchell Field, Long Island, has been awarded the fellowship in psychology offered by the Society for American Fellowships in French universities. This enables the holder to do graduate work in the French universities for two years. The purpose of the society is to develop an appreciation among American scholars of French achievements in science and learning.

DR. CHALMERS MITCHELL, the English zoologist, under the auspices of the London Times, undertook to make a flight from Cairo to the Cape with special reference to scientific observations, leaving Cairo in a Vickers-Vimy machine with a crew of four pilots and mechanics on February 6. A forced descent after delays by engine troubles at Tabora, in the Tanganyika territory damaged the machine so that the flight could not be continued.

MR. CARL L. HUBBS, assistant curator of ichthyology and herpetology in the Field Museum of Natural History, has resigned to accept the position of curator of fishes in the Museum of Zoology, University of Michigan.

ASSISTANT PROFESSOR GERALD L. WENDT, of the department of chemistry at the University of Chicago, has been appointed associate editor of the Journal of the Radiological Society of North America.

FRANK H. REED, Ph.D. (Chicago, '17), has been made supervisor of Industrial Research for the Butterworth-Judson Corporation of Newark, New Jersey.

"Growth Rate and its Influence on Structural Perfection and Mental Reactions" before the Philadelphia Psychiatric Society, on March

12.

A SPECIAL meeting of the College of Physisians of Philadelphia was held March 19, as a memorial to Dr. Horatio C. Wood. Dr. George E. de Schweinitz read a memoir to Dr. Wood. "Recollections of a Pioneer in Pharmacology in the United States," was read by Dr. Hobart A. Hare; "An Appreciation," by Dr. Francis X. Dercum, and "Reminiscences, Chiefly Neurological and Medico-Legal," by Dr. Charles K. Mills.

DR. GEORGE D. ALLEN, instructor in zoology in the University of Minnesota, died from pneumonia on March 11.

DR. K. A. J. MACKENZIE, dean of the medical department of the University of Oregon, a surgeon of national reputation, is dead at Portland, Ore., from heart disease superinduced by influenza.

UNIVERSITY AND EDUCATIONAL NEWS

THE University of Michigan has received an anonymous gift of one million dollars.

Rentals amounting to $2,367,000 will go to the university under the terms of a lease arranged by Levi L. Barbour, the Detroit manufacturer, with the stipulation that the money shall be used for educating women of the Far East.

CORNELL UNIVERSITY has received a gift of $100,000 for a new dormitory, to be named for the donors' parents, from W. G. Mennen and his sister, Mrs. Emma Mennon Williams, of Detroit.

BATES COLLEGE is to receive $500,000 from the fund to be raised by the Northern Baptist

"differentials" given by Professor A. S. Hathaway in SCIENCE for February 13, 1920, would prove highly misleading to the modern student.

Professor Hathaway defines A'y as NAy, where N is some multiplier and Ay a simple increment, and then defines dy as the limit of A'y as Ay approaches zero. The inevitable consequence of such a definition is that dy = 0, which is obviously futile.

In view of the continual recrudescence of such fallacies (with or without a historical background), it may be worth while to repeat here the modern interpretation of the differential, though this may be found correctly stated in any good text-book of calculus.

Consider the graph of a function y = f(x), with the tangent line drawn at the point x=x,, y=y. Give x an arbitrary increment

which, since x is the independent variable, may be denoted indifferently by Ax or da. Corre sponding to any such increment in x we have the increment of y, called Ay, extending up to the curve, and the differential of y, called dy, extending up to the tangent. Now when Ar (or dr) is made to approach zero, the ratio dy/dx remains constant, being the slope of the tangent line, while the ratio Ay/Ax is a variable, approaching the slope of the tangent as a limit. But the limit of Ay taken by itself is zero, and the limit of dy taken by itself is also zero.

There are thus two very good reasons why

we can not say that "dy is the limit of Ay." First, dy is a variable and therefore can not be the limit of anything; secondly, zero is the limit of Ay, and therefore nothing else can be. A list of similar fallacies, which still persist in some books (and, apparently, in some classrooms also), may be found in a paper by the present writer on "The proper use of the differential in calculus." 1

The word derivative means, of course, the ratio dy/dx.

EDWARD V. HUNTINGTON

HARVARD UNIVERSITY

WEIGHT AND CENTRIPETAL ACCELERATION TO THE EDITOR OF SCIENCE: Mr. Carl Hering's suggestion for a new form of dynamic compass1 ought to be challenged before some one organizes a company to work the idea out on a commercial basis. The fact is, of course, that the change in weight which Mr. Hering refers to occurs only when the motion is in a circle having its center in the earth's axis. Mr. Hering's disk is a plane tangent to the earth's surface and motion in this plane does not, on the basis of Newtonian mechanics, affect the weight of a body. It is understood of course, that the disk is not forced to remain tangent to the earth as the earth rotates. This would complicate the situation by introducing the gyroscopic effect. If the disk is mounted in gimbals so that the earth in turning does not force a change in direction of the shaft there would, as stated above, be no tendency of the shaft to set itself parallel with the earth's axis.

The suggestion that the light disk with equal weights at extremities of a diameter would rotate in balance when in a north and south plane, but out of balance in an east and west plane is equally mistaken. Any change in the weight of a body on the basis of Newtonian mechanics must be due to an acceleration of the body, part of the gravitational force being used to produce the accel

1 Society for the Promotion of Engineering Education: Bulletin, Vol. 4, pp. 19-28, 1914, or Proceedings, Vol. 22, pp. 115–124, 1915.

1 SCIENCE, Vol. LI., p. 46.

eration. We may, therefore, examine the accelerations of these bodies to see whether they could produce the effect described. Each of the weights on the light disk has an acceleration composed of two components. One of these components is directed toward the center of the disk. This component is due to the rotation of the disk, and may be called the disk component. Since the two weights are at opposite extremities of a diameter the disk components of their acceleration are equal in magnitude and opposite in direction, and their only effect is to produce the well-known centrifugal stress in the disk. The other component of acceleration is common to the two weights. It is the acceleration of the center of the disk due to the earth's motion. It is altogether independent of the rotation of the disk. This acceleration will affect the weights of the two bodies, but the effect will be the same for both bodies in all positions of the disk, and cannot therefore, produce unbalanced rotation.

Curiously enough there is another cause that would produce a minute unbalance in a disk of the sort just considered when rotating in any vertical plane at any point on the earth's surface. When the line of the weights is in a horizontal position let the weight of each be represented by w. Then neglecting the weight of the disk and shaft the downward pressure on the bearings is 2 w. When the line of the weights has turned through 90° to a vertical position one of the bodies has approached the earth and consequently its weight is increased. The other has receded from the earth but its weight has decreased less than the other increased since the attraction varies as the inverse square of the distance. Consequently the pressure on the bearings is greater when it is horizontal. This would produce a minute effect of unbalance which, however, would be just as great when the disk rotates slowly as when it rotates at high speed.

BURT L. NEWKIRK

UNIVERSITY OF MINNESOTA

2 Gimbal mounting is assumed again to eliminate gyroscopic effect.

THE SITUATION OF SCIENTIFIC MEN IN RUSSIA

TO THE EDITOR OF SCIENCE: The information about Professor Pavlov conveyed in a letter to SCIENCE (March 12) is somewhat puzzling in its purport. It is customary to make announcement of events which actually occurred; as for instance birth, deaths, marriages, etc. It would be a most unique procedure to treat the public to news items like these so-and-so has not yet been born, has not yet died, married, got an increase in salary. Why then this item that on a certain date A.D. Professor Pavlov was not yet dead?

It seems likely, therefore, that the only object of the note was to give publicity to a quotation from a letter of Pavlov to some other party to the effect that he was starving and instead of engaging in scientific pursuits was occupied in peeling potatoes. Now, this alleged quotation bears earmarks of a spurious nature. It undoubtedly belongs to that class of hoaxes which the daily press has been imposing upon its innocent readers with an invidious design. It is impossible to reconcile the two statements in the quotation, that Professor Pavlov is starving, and that he has so many potatoes to peel as to be obliged on that account to forsake his science. Even one not versed in the theory of nutrition would be skeptical about the probability of starvation in the midst of plenty of potatoes. (Consult Hinhede on the nutritional value of the potato.)

Like all statements intended primarily to force public opinion into a preformed mould, it is not what is actually said but what is indirectly implied that really matters. The quotation from Pavlov's letter is obviously calculated to rouse in us indignation over the sufferings of the distinguished physiologist. But does it not also insinuate a suggestion that the genius which was the man's great asset under the benign and enlightened government of the Czar of all the Russians has under the new régime become a crushing liability on him? So, ere we are moved to deep pity over Pavlov's unfortunate lot, let us re

flect if with our well-meant sympathy we may not cause him more distress than comfort. It so happens that I have some news of another venerable savant, Professor Timiriazev, distinguished botanist of the University of Moskow, an Sc.D. of Cambridge, a fellow of the Royal Society. As I have no "obvious" reason for hiding my informant, I may say that he is Arthur Ransome, whom I herewith quote:

He [Timiriazev] is about eighty years old. His left arm is paralyzed, and, as he said, he can only work at his desk and not be out and about and help as he would wish. A venerable old savant, he was siting with a green dressing gown about him, for his little flat was very cold. He spoke of his old love for England and for the English people. Then speaking of the veil of lies drawn between Soviet Russia and the rest of the world, he broke down altogether and bent his head to hide his tears. I suffer doubly-he said-I suffer as a Russian, and, if I may say so, I suffer as an Englishman. My grandmother was actually English. I suffer as an Englishman when I see the country I love misled by lies, and I suffer as a Russian because those lies concern the country to which I belong, and the ideas which I am proud to hold.

The old man rose with difficulty, for he, like every one else in Moskow, is half starved. "If I could let them know the truth-he said-those friends of mine in England, they would protest against actions which are unworthy of the England we have loved together.''

THE CREIGHTON UNIVERSITY

S. MORGULIS

RUSSIAN AND AMERICAN SCIENTIFIC MEN TO THE EDITOR OF SCIENCE: In SCIENCE of March 5, I have noticed the report that Professor Pavlov, still alive in Petrograd last summer, was peeling potatoes when last heard from. Without wishing to jest on this truly pitiable situation, it may not be amiss to submit also the report that no small portion of the professors of this country are now likewise engaged in peeling potatoes or similar menial work, at any rate for a large part of their time. Under present conditions they can not get others to do such work for them.