The potentials of certain magnetized bodies (illustrated by lantern slides): LOUIS A. BAUER, Ph.D., D.Sc., director of the department of terrestrial magnetism, Carnegie Institution of Washington. The author has had occasion in connection with various problems to establish, in a convenient form, the mathematical expressions for the potentials and field-components of certain magnetized bodies of revolution, such as, for example, ellipsoids of revolution and elliptic homeoids. The expressions usually found in treatises either stop at those for the problem of gravitation, or apply only to special cases, or they are not given in the most elegant or convenient form possible for mapping out readily the magnetic field surrounding the bodies. Not infrequently, moreover, the published expressions are found to contain errors of one kind or another. Development of magnetic susceptibility in manganese steel by prolonged heat treatment: CHARLES FRANCIS BRUSH, Ph.D., ScD., LL.D., of Cleveland. Accelerometers: N. W. AKIMOFF, of Philadel phia. Luminescence of radium salts: D. H. KABAKJIAN, assistant professor of physics, University of Pennsylvania, and E. KARRER, of Philadelphia. All radium salts luminesce in the dark at ordinary room temperature. It has been found that when a radium compound is heated to a critical temperature it will almost completely lose its luminosity while at this temperature, but when it is again cooled to room temperature it will acquire a luminosity which is many times (from ten to fifty times for radium bromide, barium bromide) its original luminosity. This property of radium compounds has been investigated as regards the following points: (1) Relation between luminosity and the maximum and minimum temperatures to which the salts have been exposed; (2) decay of the acquired luminosity with time; (3) degree of recovery of luminosity after decay by reheating; (4) relation between luminosity and chemical composition of the salt. The phenomena described in the paper can probably be explained if it be assumed that with the greater molecular freedom imparted to the salt at the higher temperatures certain groupings of molecules are formed which are stable at the higher temperatures but unstable at the ordinary room temperatures. The breaking down of these groups by the action of alpha, beta, gamma rays produces the luminescence. These groupings would correspond to the so-called "active centers" which are postulated by Rutherford in his discussion of luminescence of zinc sulphide, but differ essentially from them by the fact that these can be destroyed and reformed over and over again by heating the compound, whereas the active centers in zinc sulphide, once destroyed, can not be recovered by any simple process. Saturday Morning, April 20; George Ellery Hale, Ph.D., Sc.D., LL.D., F.R.S., Vice-president, in the Chair Motions in the stellar systems Struve 1836 and Struve 208: ERIC DOOLITTLE, professor of astronomy, University of Pennsylvania. Any double star in our catalogues may be a system of two suns, which are revolving about one another under the action of their gravitation, or their apparent connection may be only an accidental; one star may be immeasurably farther away than the other and they may only appear to be near together because they are in the same direction from us. In the latter case, measures will in time show that the one sun is drifting past the other in a straight line; in the former, the one will move about the other in an elliptic orbit. The two cases examined present especial difficulty because in each case the companion is moving directly toward the principal star in a straight line. Originally the stars were widely separated; now they are close together and are only visible as a double star in the largest telescopes. The path may be an ellipse, in which case we view it almost edgewise, and if this is the case the motion of the companion will be apparently reversed as it passes about its orbit and the motion will soon become very rapid. Observations of such systems should be secured now, while the companion is at a critical part of its path. It was found that each of the two systems examined were true physical systems and that the motion was in each case orbital. The number of the spiral nebula: H. D. CURTIS, astronomer, Lick Observatory, Mt. Hamilton, Calif. Soldiers' and sailors' insurance: SAMUEL MCCUNE LINDSAY, Ph.D., LL.D., professor of social legislation, Columbia University, New York. Italy in the Triple Alliance: WILLIAM ROSCOE THAYER, Litt.D., L.H.D., LL.D., Cambridge, Mass. Ballistic experiments by a new (?) method: ARTHUR GORDON WEBSTER, Sc.D., LL.D., professor of physics, Clark University, Worcester, and MILDRED ALLEN. Some considerations on the ballistics of a gun of seventy-five miles' range: ARTHUR GORDON WEBSTER, Sc.D., LL.D., professor of physics, Clark University, Worcester. The relation of deposits of iron and coal to the great war: WILLIAM H. HOBBS, Ph.D., Sc.D., professor of geology, University of Michigan. The peculiar geographical features of northeastern France and their bearing on the war: WILLIAM MORRIS DAVIS, Sc.D., Ph.D., professor emeritus of geology, Harvard University. The strata of the socalled Paris basin lie nested in one another, like a series of broad and shallow platters, the largest one beneath, the smallest one above, but the edges of all of them reaching to about the same altitude, except that the less resistant layers have been worn down somewhat lower than the more resistant ones. As a result, the more resistant layers rise in upland belts of moderate altitude above the intermediate depressions, and both the uplands and the depressions are arranged in concentric arcs around Paris as a center. Eight of these upland belts may be counted in northeastern France, where they dominate the topography. The arrangement of the rivers with respect to the uplands is varied and peculiar. The local features between Verdun on the Meuse and Lunéville on the Meurthe are best understood when described in terms of the upland belts, the depressions and the river valleys. Rig-veda repetitions: MAURICE BLOOMFIELD, Ph.D., LL.D., professor of Sanskrit and comparative philology, Johns Hopkins University. The Babylonian origin of the Jewish method of slaughter: PAUL HAUPT, Ph.D., LL.D., professor of Semitic languages, Johns Hopkins University. Saturday Afternoon, April 20; William B. Scott, D.Sc., LL.D., president, in the Chair Symposium on food problems in relation to war: Introductory remarks: ALONZO E. TAYLOR, M.D., professor of physiological chemistry, University of Pennsylvania. Physiological effects of prolonged reduced diet on twenty-five men: FRANCIS G. BENEDICT, Ph.D., Sc.D., director of the nutrition laboratory of the Carnegie Institution of Washington. The possibility of facing stringent food shortage made it desirable to study with the greatest accuracy the physiological effects of a prolonged reduced ration upon a group of healthy young men. Twenty-five men in two squads, volunteers from the International Y. M. C. A. College in Springfield, Massachusetts, were placed upon a reduced ration, approximately one half the number of calories, and at the end of about two months had lost 10 per cent. of their body weight. From there on the calories were adjusted to hold the weight at a constant level. A long series of measurements of the basal metabolism, the neuro-muscular processes, strength tests, etc., as well as a careful clinical examination, were repeated from day to day. The men showed remarkable stamina in the face of the reduced ration, carried out all of their activities, academic and physical, in connection with their college life, and, aside from obvious degree of emaciation, presented no unusual picture. A marked reduction in calories in the intake was effected. Food conservation from the standpoint of the chemistry of nutrition: HENRY C. SHERMAN, Ph.D., professor of food chemistry, Columbia University, New York City. Some economic aspects of the American food supply: J. RUSSELL SMITH, Ph.D., professor of industry, Wharton School of Finance and Commerce, University of Pennsylvania. One of the first acts of the government with regard to the bread supply was to interfere with the law of supply and demand by guaranteeing increased home consumption and reduced home production. Despite innumerable reports that maximum price fixing had been unsatisfactory in Europe, we tried it. As one of the first big steps in the United States we reduced the maximum price of wheat at a time when more wheat was needed. We also fixed a minimum price for the 1918 crop lower by a dollar than the price prevailing in the spring of 1917. The American farmer quietly but effectively made his answer. The government, through the Department of Agriculture, called for planting of 47,337,000 acres of winter wheat, and it got 11 per cent. less than this, or 42,170,000, almost exactly the amount sown in 1914. Probably the worst part of this wheat price fixing is that it resulted in a destructive price ration. The high prices of meat pushed the price of corn to such a figure that in many parts of the country it was cheaper to feed the pigs on wheat and rye than on corn, and you may depend upon it many of these four-footed brethren got the breadstuff. In some parts of New York state wheat was 40 to 50 cents a bushel higher than corn. The production of such a condition by legislation as our Congress brought about is not to be called food conservation. It is food destruction. As an outraged citizen I protest against legislation that makes me eat corn and makes the pig eat wheat. If I were a pro-German I would secretly applaud it. Food control and food conservation in the United States army: JOHN R. MURLIN, Major, Sanitary Corps, N. A. ARTHUR W. GOODSPEED, SCIENCE A SURVEY OF AMERICAN BIOLOGICAL CHEMICAL LITERATURE1 ABOUT a year ago Sparks and Noyes2 prepared a census of the periodical literature of chemistry published in the United States. They selected for their study the five American chemical journals: American Chemical Journal Journal of the American Chemical Society Journal of Biological Chemistry Journal of Industrial and Engineering Chemistry Journal of Physical Chemistry This study showed that during the five-year period, 1909-1910 to 1914-1915, the Journal of Biological Chemistry gained 150 per cent. in the number of published pages; the Journal of Industrial and Engineering Chemistry, 78 per cent.; the Journal of the American Chemical Society, 88 per cent.; while the Journal of Physical Chemistry showed a loss in published pages of only 2 per cent. (The American Chemical Journal was merged with the Journal of the American Chemical Society in 1914). With this study as a model and an incentive, the writer has made a somewhat similar investigation of the biological-chemical literature during the period 1907-1916. The question as to what properly belongs under the heading biological chemistry is probably open to discussion. It seems fair, however, to accept the decision of the men who are in charge of the various sections of the Biological Chemical division of Chemical Abstracts. All papers which are found in 1 This study was presented before the Second Annual Conference of Biological Chemists, held at the Chemist Club, New York City, December 31, 1917. 2 Sparks, Marion E., and Noyes, W. A., SCIENCE, 1917, 45, 168 (February 16). this division have been considered in this study.3 Journal of Immunology 1916 Quarterly Cumulative Index to Current Medical Literature 1916 1917 1917 . 1917 1917 American Journal of Syphilis The number of journals which have sprung into existence since 1914 is very noticeable. Many of these probably owe their existence, in part at least, to the fact that publication in German magazines was cut off by the war. It is to be hoped that they may survive after the war, when many scientific investigators will again be tempted to publish in German. Special attention should be directed to the two abstract journals. Chemical Abstracts is by far the most complete abstract journal published in any language. It covers nearly 700 periodicals (671 titles are given in the 1915 list; many have been added since then, as the 1917 list, shortly to appear, will show. Still others are covered through other abstract journals, about a dozen of which are regularly checked). The Biological Abstracts, so well edited by his staff, are especially complete. organized by Professor Gies, and carefully Very few, if any articles of biological interest are missing. The fact that about 10,000 copies are in circulation must add to the value of American scientific research. Abstracts of Bacteriology covers a similar field for the bacteriologist and appears to be equally well organized. And finally, the Cumulative Index of Current Medical Literature, issued quarterly, gives in one index the current medical and biological literature. We are grateful for these publications, whether we express it or not. They lighten very much the burden of reference hunting. The following journals have been used in the study recorded here: American Journal of the Diseases of Children Journal of the American Chemical Society unexpected places. It would be of interest to compile a complete list of all the work of biological chemistry published by the various American laboratories in all the periodicals, American and foreign. This the writer must leave to some one else. Table III. contains a list of the total number of articles and the number of those of biological-chemical nature, and in some cases, the number of pages. As Sparks and Noyes pointed out, and as many others have remarked in discussing the subject, the number of pages has no real significance in many instances. Many short articles are of more value, scientifically, than other articles with their hundreds of pages. The length of an article depends too much upon the nature of the subject and the personality of the writer, and not enough upon its scientific value. Table IV. contains a comparison of the number of articles (and pages in some instances) in those periodicals published during the periods 1907-1908 and 1915-1916. In those cases where the periodical was not published in 1907, the figures for the later period are given for comparison. These tables bring out, rather forcibly, first, the large amount of biological work which is being carried out in this country, and second, the marked increase in this kind of research during the past decade. The curve will drop |