(2) So that this plane is perpendicular to the field.

If we are able to calculate the refractive indices on these data, then it must be possible to find conditions governing the arrangement of the atoms, when we know the composition of the crystal and its refractive indices. For instance, the near equality of the refractive indices of potassium sulphate implies that the dielectric capacity of the SO, group is much the same in all directions, and this is in agreement with the hypothesis that the oxygen atoms are grouped in some sort of tetrahedral fashion about the sulphur atom.

There are still other connections between structure and properties which we begin to understand, and can use in proportion to our understanding. The cleavage plane, and the occurrence of certain faces in preference to others are connected with the nature of the bonds and the size of the spacings. We are not surprised to find that in bismuth or graphite or naphthalene the cleavage plane cuts across the ties which we should expect to be the weakest of those that bind the molecules together; or again, that natural faces follow the planes that are richest in atoms or molecules and may be assumed to contain relatively large numbers of linkages. In naphthalene the cleavage plane passes between the ends of the molecules, where the ẞ hydrogens are, and where there is a deficiency in the number of scattering centers, as the X-rays indicate by the strengths of several orders of the (001) reflection. The other faces found on the crystal cut across the ties at the positions of the a hydrogens.

There are many other connections between the structure and other properties of a substance, such as dielectric capacity, rigidity and compressibility, conductivity both thermal and electric, magnetic constants. In fact, the only properties of solid bodies which are not directly and obviously related to crystal structure are those, few in number, that depend on atomic characteristics alone, such as weight; and the absorption coefficients for a, ẞ, y and X rays, all the rays which involve high quantum energies. With few exceptions every aspect of the behavior of a solid substance depends on the mode of arrangement of its atoms and molecules. We have, therefore, an immense field of research before us, into which the X-ray methods have provided an unexpected and welcome entrance.

They tell us directly, as I have said, the number of molecules in the crystal unit cell, and the mode of their arrangement with such determination of lengths and angles as are required to define the mode of arrangement in full. They leave us then to ally our new knowledge to all that we possess already as to the physical and chemical properties of substances.

By this comparison we hope in the end to determine the position of every atom, and explain its influence through its nature and position upon the properties of the substance. It is the chemistry of the solid that comes into view, richer in its variety even than the chemistry we have studied for the past century, and Every side of scientific activity takes part in this possessing an importance which is obvious to us all.

advance, for all sciences are concerned with the behavior of matter.

W. H. BRAGG

REMINISCENCES OF LORD KELVIN

ON the hundredth anniversary of the birth of Lord Kelvin, celebrated by the scientific world, it may be permitted for the writer to record personal experiences of his kindness and impressions of his interesting personality.

When in England among the scientists in the late eighties of the last century, it was most gratifying to receive from Lord Rayleigh a letter of introduction to Sir William Thomson. When Lord Rayleigh came to America to attend a meeting of the British Association in Canada, he visited the laboratories of Wellesley College and was graciously disposed to put in the way of the first woman undertaking a department of physics in a college access to the best in her subject in England.

Though it was summer and vacation in the University of Glasgow, there was received from Lady Thomson a cordial letter, stating that she and Sir William were to come up from their country place in Ayrshire to assist in doing the honors in the university for the British Medical Association, then in session. She enclosed a card of invitation to the reception to be given to the medical men and asked me to come at nine o'clock to go with them.

At the appointed hour I was welcomed by our host, a man of quiet, almost quaint appearance and manner, but shining from his kind eyes a winning friendliness. Lady Thomson, in garnet velvet, tall and handsome, quite resplendent with pearls and diamonds, stood beside him. The reception was in the stately Gothic senate chamber, lately given to the university by the Marquis of Bute. All the faculty in academic dress and the ladies were gathered on the daïs.

After being presented to Principal Caird and others, from a point of vantage amid the brilliant group, one saw all Glasgow, much of Edinburgh and the British doctors file past.

It was evident that Lady Thomson was the acknowledged social leader, and that Sir William was the one whom all the guests were most eager to meet.

The next day several memorable hours were spent

in the laboratories, where much was going on. Half a dozen alert young students, some of whom have since become distinguished, were at work; here they were hands and feet under the control of the master mind, trying one device and then another to overcome difficulties in the performance of instruments later perfected. I sat by and watched how the mind of the original investigator works. His luminous face was an interesting study. Later he explained the evolution of his quadrant electrometer and siphon recorder, showed early models of cable devices and told dramatic experiences on his three Atlantic cablelaying voyages.

He told of Maxwell's great works-said he had not mastered all his equations yet-"I took a pull at them after returning from the reception the night before" he added. Lady Thomson showed the notebooks he always kept about to catch new ideas or develop old ones; sometimes these were called to service in the night, which reminds one of Emerson, who used to wake up his wife because he had a thought. Sir William took me to his lecture room; showed his shoemaker's-wax experiment, in which the lead bullets from above and the wooden cubes from below were working their way through, as he conceived the earth ploughs through the ether. He showed his "secular experiment," as he called it, which he said was to go on for a hundred years to show the rate of travel of molecules. One wonders if that long tube is still on the wall of the Glasgow laboratory.

Going to the house for tea, the African parrot was introduced "Dr. Red-tail, alias Parnell or Donnelly, because he is an obstructionist, and if he can not have his way makes it impossible for others to have theirs."

Sir William talked of Scotch history, of Prince Charlie and Jacobite music, of Highland legends, of American politics.

In contrast to many other English and German scientists, Sir William seemed neither surprised nor alarmed that a woman should devote herself to mathematics and physics. This was thirty-five years ago. Some months later the meeting of the British Association of Science was at Bath. It was an epochal meeting, for the work of Hertz, showing the identity of light and electricity, thus verifying the prediction of Maxwell, was just being discussed and "Section A" was full of excitement. The American stranger was taken under the kind care of Lady Thomson, who was always at her husband's elbow, correcting his proof or amending his absent-mindedness, saying, "Sir William, here is so and so, you must meet him." Through their kindness a dinner at the beautiful home of their host, a nephew of John Bright, was enjoyed. It was worth while to listen to the brilliant

conversation between Sir William and Jannsen, the distinguished French astronomer, Oliver Lodge, Glazebrook and other like guests.

After ten years it was again my good fortune to be at another notable meeting of the British Association at Liverpool. The x-rays had just been discovered, and Lenard, who did the pioneer work, was a guest of honor. It was here a sidelight on the personality of Lord Kelvin, for he had now been elevated to the peerage, to see how all the Englishmen of science not only revered but loved him.

To hear the veterans, Kelvin and Stokes, in high debate with other giants of science as to the "particular go" of the half dozen new kinds of radiation lately discovered was something to remember.

Lord Kelvin asked me to a private séance with Lenard and his tubes. His child-like ingenuousness was delightful. While every one was hanging on his words, his attitude was always that of the questioner and learner.

This was deeply impressed in the final experience I had with Lord Kelvin. He was to lecture in Faraday's Theater in the Royal Institution in London. Professor Dewar sent tickets and an invitation to a reception given at his house after the lecture. It had became a rare thing for Lord Kelvin to lecture, and a notable audience was gathered from all the universities to honor the occasion. Every one was in full dress, as is the wont at these famous Friday evening lectures. The semi-circle of men fronting the lecturer was remarkable, every man of international reputation-Lord Rayleigh, who discovered argon, Ramsay, of helium fame, Crookes, of the cathode rays, Huggins, "father of the new astronomy," and a score of others almost as noted. Lord Kelvin spoke slowly, with singular unconsciousness of his audience. He seemed to be rather thinking aloud and watching his experiment with intent look and uplifted finger, looking for the result as if to learn something new himself.

Lord Kelvin was great enough to lead the mathematical physicists of his day and kind enough to give the inspiration of his talk, and answer patiently the questions of eager young students.

SARAH FRANCES WHITING

SCIENTIFIC EVENTS

THOMAS CORWIN MENDENHALL

A MEMORIAL to Dr. Thomas Corwin Mendenhall, prepared by the committee on necrology, was presented at the meeting of the Ohio Academy of Science at Columbus on April 19, by Professor Herbert Osborn. The memorial reviews Dr. Mendenhall's life and services to science, which were the subject of a special article by Mr. G. R. Putnam

printed in the issue of SCIENCE for July 11, 1924. The concluding part of the memorial of the Ohio Academy is as follows:

Dr. Mendenhall's active connection with our Ohio Academy of Science began shortly after his return to Ohio in 1912 and he has been a devoted and helpful member interested in promoting its every interest. Almost as soon as he had acquired membership he was elected president, a quite unusual proceeding. This occurred at Oberlin meeting, 1913, and he served for the year 1914 with such skill and enthusiasm as to give us all renewed courage and confidence in the mission of the academy. As trustee and for a number of years chairman of the research fund of the academy, serving from 1916 to his death, he was greatly interested in the use of the academy funds for research and used rare discrimination in the assignment of its limited income to secure the largest benefits in the encouragement of research.

He was particularly interested in the securing of larger support for the academy, and served most faithfully on the legislative committee which sought state support for the academy activities, especially for publication of the results of scientific studies. He expressed the hope, and it was one of his cherished projects, that the academy might be provided with a suitable building for its permanent home and as a center of its activities and that it might serve in some very vital way for the promotion of the scientific functions of the state. His recommendations and suggestions are matters of recent record and may serve us in our future efforts for the development of scientific activities in the state.

With all these relations the thing we feel most deeply to-day is the friendly nature of his work among us. With the most unusual experience in scientific development of more than half a century, a remarkable acquaintance with scientific work and workers he possessed such a broad appreciation of the work and accomplishments of others and such a friendly attitude toward even the most humble worker in the field of science that his presence and interest were a constant source of encouragement. With a multitude of honors and distinctions he was still one of the most democratic and unassuming of men. With a wealth of achievement, seldom equalled, to his credit he was ever modest in reference to the importance of his own contributions to science. He was a man whom we could admire and love, whose friendly greetings will be missed but whose memory will be cherished as representing the finest spirit of scientific devotion, achievement and fellowship. We have recorded our esteem and appreciation of his worth in such honors as it was in our power to give. We have now to place on record, as our lasting recognition, this declaration of our high regard for his service, our great indebtedness for his many activities in the academy and our tribute to his memory as a friend and fellow worker. His fine accomplishments and inspiring personality will long remain with us as a beautiful

memory.

HERBERT OSBORN, Chairman,
A. D. COLE,
Wм. MCPHERSON

MINNESOTA EXPEDITION TO THE

HAWAIIAN ISLANDS

THERE has been organized at the University of Minnesota an expedition to the Hawaiian Islands to make a survey of the marine fauna and flora along the coast, with special reference to the algae and the food of fish. Members of the expedition include: Dr. Josephine Tilden, professor of botany; Dr. W. A. Riley, chief divisions of entomology and economic zoology; Dr. Henry A. Erikson, chairman, department of physics; Dr. R. A. Gortner, professor of plant physiology; Dr. J. Arthur Harris, professor of botany; Dr. Shirley P. Miller, instructor of anatomy, and Dr. Royal N. Chapman and Dr. William E. Hoffman, of the department of zoology.

The occasion of the trip is the First Pan-Pacific Food Conservation Conference. Members of the Minnesota group are among the delegates representing the United States. Following the termination of the conference the group will remain for the rest of the summer in the Hawaiian Islands where they will begin their research investigations which are closely related to the purposes of the conferences. This work will be a cooperative study of the plants and animals inhabiting the waters bordering on the islands with especial emphasis upon their relations to the production of human food.

THE PRIZE ESSAY AWARDS OF THE AMERICAN CHEMICAL SOCIETY

ACCORDING to Industrial and Engineering Chemistry, Secretary of Commerce Herbert Hoover, chairman of the National Awards of the American Chemical Society, has announced that six four-year scholarships to Yale University, consisting of tuition fees. and $500 a year in cash, have been awarded to the following students:

DONALD VIVIAN, Phoenix, Ariz., "The relation of chemistry to health and disease."

JAMES C. REID, Dallas, Texas, "The relation of chemistry to the enrichment of life."

OLIVER C. PITTMAN, Commerce, Ga., "The relation of chemistry to agriculture and forestry."

ELTON R. ALLISON, Centralia, Wash., "The relation of chemistry to national defense."'

BENJAMIN NASSAU, Hartford, Conn., "The relation of chemistry to the home."

The contest will be continued next year, and in addition to the prizes offered to students of high and secondary schools, which will be substantially the same as those awarded this year, six prizes of $1,000 each will be awarded to students of colleges and universities for the six best essays on the subjects designated:

"The relation of chemistry to health and disease.''

"The relation of chemistry to the enrichment of life.'' "The relation of chemistry to agriculture or forestry." "The relation of chemistry to national defense.'' "The relation of chemistry to the home."' "The relation of chemistry to the development of an industry or a resource of the United States.”

Universities granting scholarships in addition to those provided by Mr. and Mrs. Garvan are the University of Arizona, which gives two scholarships remitting all fees; the University of Iowa, one scholarship; the University of Kentucky and the University of Mississippi, each one. In South Dakota the Northern Normal and Industrial School at Aberdeen offers a prize of $25 for the best essay submitted in the state. In Texas the Baylor College for Women offers a scholarship worth $120, and the University of Texas offers a tuition scholarship worth $120. The University of Utah has contributed a tuition scholarship, and Washington and Lee University in Virginia is offering a tuition scholarship worth $80. Both the Catholic University of America and Georgetown University will grant four-year tuition scholarships, while the University of Virginia offers a four-year scholarship to the author of the best essay submitted in that state. The University of Florida will award two oneyear scholarships remitting registration and laboratory fees; Northwestern University offers one scholarship; the University of Maryland offers a tuition. scholarship; St. Louis University, a four-year scholarship, including matriculation fee; and the University of Missouri has established six fellowships for the six prize-winning essays in Missouri.

PSYCHOLOGICAL RESEARCH AT YALE

UNIVERSITY

AN important development of the research work in psychology at Yale, the appointment of three men of national distinction, and the gift of funds to carry on the new work are for the first time definitely announced by Yale University.

A group of research specialists will be associated together in an institute devoted to the study of fundamental problems of human behavior, and to the training of personnel for the further pursuit of new studies in the field of teaching, research and of practical application. The initiation of this enterprise is a step of the first importance toward increasing the facilities for psychological research and training.

The need of such research has been increasingly felt in medicine, in industry, in education, in social work, in child welfare and in various public problems. A generous contribution for a period of five years toward this undertaking has been made by the Laura Spelman Rockefeller Memorial.

Roswell Parker Angier, professor of psychology in Yale University, will act as chairman of the group or institute, which will be an integral part of the university. It will be closely associated with the graduate school; its facilities will be available to advanced students who may be candidates for a doctorate or who may wish to engage independently in research.

Arrangements have been concluded for bringing to the institute three leading men of science. Robert M. Yerkes, formerly of the National Research Council, will have charge of the work in the field of comparative psychology with special reference to the primates; Raymond Dodge, formerly professor of psychology in Wesleyan University, in fundamental aspects of normal behavior, and Clark Wissler, of the American Museum of Natural History, in the fields of racial, and particularly primitive, human behavior in its cultural and social aspects.

SCIENTIFIC NOTES AND NEWS

AT the meeting of the British Association for the Advancement of Science, held in Toronto from August 6 to 13, general lectures were delivered as follows:

Evening discourses.

SIR THOMAS HOLLAND on "Formation and destruction of mineral deposits.''

PROFESSOR D'ARCY W. THOMPSON, of St. Andrews University, on "The shell of a nautilus."

Citizens' lectures.

PROFESSOR A. S. EDDINGTON, of the University of Cambridge, on "Einstein's theory of relativity." PROFESSOR G. H. F. NUTTALL, of the University of Cambridge, on "Cambridge."

SIR ROBERT ROBERTSON, of the Royal Arsenal, Woolwich, on "Explosives.''

Lectures to children.

SIR WILLIAM BRAGG, of the University of London, on "Crystals.'

L. H. DUDLEY BUXTON on "The people who live beyond the great wall of China.''

PROFESSOR J. H. PRIESTLY, of the University of Leeds, on "Plant waterproofs.'

THE annual meeting of the French Association for the Advancement of Science was held in Liége from July 28 to August 2, under the presidency of Professor M. Viala. This is the first time that the asso

ciation has met outside France. The King of Belgium presided at the opening meeting, when the medal of the association was conferred upon M. Poincaré and Cardinal Mercier.

DR. WARO NAKAHARA, of the Rockefeller Institute for Medical Research, has been awarded the degree of doctor of medical science by the Imperial University of Kyoto, Japan, in recognition of his work on cancer immunity.

THE Royal College of Surgeons of England has awarded its Lister Medal for distinguished contributions to surgical science, with the honorarium of £500, to Sir W. Watson Cheyne, who, in accordance with the conditions of the trust, has undertaken to give an address at the Royal College of Surgeons next year.

THE Cagnola prize (gold medal and 2,500 lire) has been awarded by the Lombardy Academy of Sciences to Dr. E. Greppi, of Milan, for his studies on hemoglobin.

THE Leibniz Silver Medal, for 1924, of the Prussian Academy of Sciences has been awarded to Fraulein Lisa Meitner, professor of physics at the Kaiser Wilhelm Institute in Dahlem, near Berlin, in recognition of her researches on radium.

FOR the year 1924 the American Geographical Society of New York has awarded its three gold medals as follows: The Cullum Geographical Medal to Professor Jovan Cvijić, of Belgrad University, for his contributions to Balkan geography; the Charles P. Daly Medal to Colonel Claude H. Birdseye, who descended the Grand Canyon of the Colorado in the summer of 1923, in charge of a party studying the water-power possibilities of the canyon; the David Livingston Centenary Medal to Commander Frank Wild, well known for his Antarctic work.

MEDALS of the Royal Geographical Society have been awarded as follows: The Founder's Medal to Ahmed Hassanein Bey for his journey in 1923 to Kufra and Darfur; the Patron's Medal to Commander Frank Wild for his long services to Antarctic Exploration. The council have awarded the Victoria Medal to J. F. Hayford, formerly of the United States Coast and Geodetic Survey and now director of the College of Engineering of Northwestern University, for his establishment of the theory of Isostasy; the Murchison Grant to J. H. Reynolds for his work on the 1/Million Map and for the Permanent Committee on Geographical Names; the Back Grant to M. C. Lester for his geographical work in Graham Land; the Cuthbert Peek Grant to F. Kingdon Ward to assist him in his present journey in Tibet; the Gill Memorial to Major A. L. Holt for his surveys in Arabia.

AT the annual general meeting of the Faraday Society, held on July 7, in London, Professor F. G. Donnen was elected to succeed Sir Robert Robertson as president.

PROFESSOR MICHAEL I. PUPIN and Dean George B. Pegram, of the Schools of Mines, Engineering and Chemistry, have been designated to represent Columbia University at the centenary of the Franklin Institute, Philadelphia, September 17 to 19.

PROFESSOR VLADIMIR KARAPETOFF, of the school of electrical engineering at Cornell University, has been nominated on the Socialists' New York State ticket for the office of state engineer and surveyor. Two years ago the late Dr. Steinmetz was the socialist party's nominee for the same office.

D. B. Dow, of the Petroleum Experiment Station of the Bureau of Mines, has been appointed engineer in charge at the new station now being established at the University of Wyoming.

HENRY C. BERGER has resigned from the research staff of the U. S. Bureau of Mines to take the position of research chemist for the Armstrong Cork and Insulation Company, New Jersey.

DR. R. E. M. WHEELER has been appointed director of the National Museum of Wales, in succession to Dr. William Evans Hoyle, who resigned the position recently owing to ill health.

DR. C. V. PIPER, of the United States Department of Agriculture, who has been studying pastures and meadows in Europe, returned in the latter part of

July.

THE orator at the University of Chicago, at the convocation on August 20, will be Professor John Merle Coulter, head of the department of botany at the university, whose subject is "The international mission of universities."

A BUST of the late Professor Blanchard, the parasitologist and authority on tropical medicine, has recently been unveiled at his birthplace, Saint-Christophe, in Touraine.

THE Société d'Anthropologie of Paris recently celebrated the centenary of the birth of Paule Broca, who founded the society in 1859.

THE death is announced of Dr. David Lobo, emeritus professor of obstetrics and rector of the Central University of Venezuela, recently president of the National Academy of Medicine.

DR. FILIP POČTA, professor of paleontology and geology at the University of Prague, died recently at the age of sixty-five years.

THE death is also announced of M. Emile Pierard,