Johns Hopkins University

SCHOOL OF MEDICINE

The School of Medicine is an Integral Part of the University and is in the Closest Affiliation with the Johns Hopkins Hospital.

COURSES FOR GRADUATES

In addition to offering instruction to students enrolled as candidates for the degree of Doctor of Medicine, the School also offers Courses for Graduates in Medicine. In each of the clinical departments opportunity for advanced instruction will be offered to a small number of physicians, who must satisfy the head of the department in which they desire to study that they are likely to profit by it.

Students will not be accepted for a period shorter than three academic quarters of eight weeks each, and it is desirable that four quarters of instruction be taken. The courses are not planned for purposes of review but for broad preparation in one of the lines of medical practice or research. The opportunities offered will consist in clinical work in the dispensary, ward-rounds, laboratory training, and special clinical studies.

The academic year begins the Tuesday nearest October 1 (October 4, 1927), and students may be admitted at the beginning of any academic quarter. The charge for tuition is $50 a quarter, payable in advance.

Inquiries should be addressed to the Executive Secretary of the School of Medicine, Johns Hopkins University, Washington and Monument Streets, Baltimore, Maryland.

School of Tropical Medicine

of the

University of Porto Rico

under the auspices of COLUMBIA UNIVERSITY

San Juan, P. R.

An institution for the study of tropical diseases and their prevention.

New building containing well equipped laboratories and library. Clinical facilities in general and special hospitals. Field work in cooperation with Insular Department of Health.

Courses in bacteriology, mycology, parasitology, pathology, food chemistry, public health and transmissible diseases, open to graduates in medicine and others having equivalent preparation. Number of students limited.

First term of second session begins Oct. 1, 1927; second term, Feb. 1, 1928. Special students and investigators admitted at other times as space and circumstances permit. In all cases arrangement in advance is advised.

For further information apply to

Director

School of Tropical Medicine San Juan, Porto Rico.

pressures attain a maximum of 276 pounds per square inch. Besides steam, various gases come out of the wells, making up less than two per cent. by volume of the product.

Similar wells have been operated on a large scale for several years in Italy. Concerning these, Dr. Day remarked, "Compared with the development of natural steam in Tuscany, where more than 30,000 H.P. is now commercially developed, the conditions in California appear to be somewhat more favorable from the point of view of the uncondensable gases carried and their corrosive effect upon metals. The total power available is probably smaller. The oldest of the California wells has now been flowing intermittently for five years with undiminished pressure.''

VANADIUM

THE addition of a new metal, vanadium, to the world's resources, is announced by J. W. Marden and M. N. Rich, research scientists of the Westinghouse Lamp Company. Vanadium has been known in its compounds for a long time, according to Dr. Marden and Dr. Rich, but in spite of a century of efforts on the part of chemists no one has previously been able to produce it in its pure form. The method employed by the authors is to heat a mixture of vanadic oxide, metallic calcium and calcium chloride in an electric furnace for an hour at a temperature of nearly 1,400 degrees Fahrenheit. After cooling and stirring the resulting mass in cold water, metallic vanadium is obtained in the form of beads.

"The beads of vanadium are very bright, have a steelwhite color and are quite malleable, soft and ductile,' say the authors. "They can be melted in a vacuum in a high-frequency induction furnace, rolled into wire and worked up into other shapes. As far as analysis can determine, they are 99.9 per cent. pure metal.

"There is no known use for this new metal at present, but undoubtedly it will have special properties that will make it useful. Tungsten, for example, was once a useless metal, but is now of inestimable value for filaments in incandescent lamps, for high-speed tool steel alloys and many other purposes. Vanadium may, in time, prove equally serviceable.''

ITEMS

USING an electrical heat-measuring device so incredibly delicate that it is sensitive to two trillionths of an ampere of current and will measure temperature changes of as little as one ten millionth of a degree Centigrade, Dr. A. V. Hill, of Cornell University, has measured the temperature changes in nerve fibers during their activity. In describing his experiments before the National Academy of Sciences, he stated that his object had been to learn more about the nature of nervous action. Older theories have held that nervous impulses were not like other physiological processes, but were physical waves like light or radio waves. These ideas were based on the absence of any detectable heat given off by nerves as a result of stimulation. But with the extremely sensitive instrument devised by Dr. Hill it is possible to measure

the almost vanishingly minute temperature rise that occurs in a single nerve fiber when it is caused to react. The moment of activity of a nerve is followed by a prolonged period of recovery, during which nine times the initial amount of heat is given off.

THE loss in weight that we all undergo every day has been the object of research by Dr. Francis G. Benedict and Cornelia Gollay Benedict, of the Carnegie Institution of Washington, who reported their results at the recent meeting of the National Academy of Sciences. Two sensitive balances were used in the work. Both were strong enough to sustain the weight of a man, but sensitive enough to register small changes in weight. One of the balances would indicate a change of one third of an ounce, and was so constructed that the volunteer for the experiment could sleep all night on its platform. The other was a hundred times as sensitive, but could be occupied for only an hour or so at a stretch. The total moisture losses of this class from a woman of average weight were found to average around 30 grams, or one ounce, per hour; for a man the figure was about one third higher. An auxiliary device permitted the separate measurement of losses from the lungs and skin, and these averaged 50 per cent. from each source of water loss. Other mechanisms measured the carbon dioxid given off, the percentage of water in the outgoing breath and also its temperature.

A NEW process for making sugar out of sawdust was described by Professor Erik Haegglund, of Abo, at the coal and wood chemistry conference recently held in Stockholm, where he reported that at Geneva, where the process is being tried on a commercial scale, from 65 to 70 per cent. of the sawdust by weight can be converted into sugar. For Sweden, where forestry is one of the dominating industries and where most of the sugar has to be imported, the method is likely to become of the greatest importance. Several hundred thousand tons of "wood sugar" can be produced annually from easily accessible raw materials.

BECAUSE it resembles a star twinkling at night more than any other precious stone, the blue zircon of Siam has been rechristened "Starlite" by Dr. George F. Kunz. These flashing blue stones from Siam are unusual in that they are never blue at all when found in their natural state, but are brown or reddish in hue. The stones are placed in a crucible and burned in a fire from six to eight hours exposed to a solution of cobalt nitrate and potassium ferrocyanide, said Dr. Kunz, in announcing the new name to the New York Mineralogical Society. The chemicals do not touch the stones which are being changed in color, but the fumes do the coloring. After cutting it is necessary to expose them again to the fire from five to twenty minutes. This is the most brilliant blue and green precious stone. The flash is more near that of the diamond of the same color and resembles the occasional sparks from copper contacts, especially when a trolley pole hits a wire. It also has the brilliancy and color of some stars.

FOSSIL IMPLEMENTS IN PLIOCENE

DEPOSITS

Copyright, 1927, by Science Service

HAS Nebraska produced the most ancient evidence of the existence of man yet known to science? This question is raised by Dr. Henry Fairfield Osborn, president of the American Museum of Natural History, in a report to the American Philosophical Society in which he describes investigations conducted by him in collaboration with Albert Thomson, of the American Museum staff. Fossil bone implements in geologic strata have been unearthed that may be some 4,000,000 years old, an age known to geologists as Pliocene.

Since past opinion has been that the most ancient evidences of man were to be found in the Old World, and since claims of the discovery of man in America antedating the Indians, some 25,000 years ago, have been received heretofore with skepticism, the announcement of Dr. Osborn, one of the world's leading authorities on the antiquity and evolution of man, will create great scientific interest.

Over 300 implements of forty different types have been discovered. They are made of the bones of extinct animals that lived in Pliocene times, but time has caused them to be turned into stone. These are the first completely fossilized bones to be discovered. Among the animals whose bones are represented in the collection are extinct horses, camels, deer, elephants and mastodons.

The exact locality in which the discovery was made has not yet been announced with further detail than to state that it is in western Nebraska. Dr. Osborn explained that he desired to protect the site from curiosity seekers who might interfere with the scientific investigations. The first of these artifacts were discovered about two years ago and since that time tractors and other modern machinery have been used in excavating the area. Two localities about 75 feet apart have produced most of the implements.

The fossilized implements are described by Dr. Osborn as of undoubted human origin and of symmetrical shape. Among them are skin dressers for cleaning animal hides, pointed awl-like implements evidently used in sewing, neck ornaments made of strung bones and a kind of comb that seems to be a tattooing implement. Eighteen of the types of tools have been matched with counterparts found in the ruins of cliff dwellers of the arid regions of the Southwest and one type can be nearly duplicated by a much more recent implement from the shell heaps of eastern America. Dr. Osborn stated that the fossilized bone implements he has found are just as real artifacts of human handiwork as are the famous worked flints of Europe. But unlike the implements of Europe which are usually weapons and hunting tools, the Nebraska artifacts are nearly wholly related to the peaceful arts. Further investigations are to be carried on this summer.

The discovery of evidences of ancient man in Nebraska,

the native state of William Jennings Bryan, recalls that a fossil tooth found there several years ago by Harold Cook was ascribed by Dr. Osborn to a new type of ancient man, who may have been the maker of the tools and ornaments now unearthed. Dr. Osborn's discoveries also lend added interest to the recently reported discovery by investigators at the Colorado Museum of Natural History of evidences of ancient man in Pleistocene deposits in three widely separated localities in the West.

CHEMICAL ANALYSIS OF THE TUBERCULOSIS GERM

CHEMICAL analysis of the germ that causes tuberculosis has led to the discovery of a new type of compound, a phosphorus-containing fat, which has peculiar biological properties, according to Professor R. J. Anderson, of the department of chemistry at Yale University.

The tuberculosis bacterium is unique among single-celled organisms in being the possessor of a waxy covering which renders it highly resistant. This is why it can defy the phagocytes which police the body, for instead of being dissolved by them and destroyed, the T. B. organism survives and may multiply after being engulfed. The waxy sheath is so thick that it makes up one fifth to two fifths of the weight of the dried bacteria.

Professor Anderson extracted eight pounds of the germs with a mixture of alcohol and ether to dissolve out this waxy coating. He obtained a pound of wax, half a pound of fat proper, and half a pound of phosphatide or phosphorus-containing, fat-like substance. The last material, to which he has given the name phosphosucride, is the most unusual constituent of the germs. It has been shown to contain phosphoric acid, a sugar and fatty acids. This compound differs from all other known phosphorized fats, according to Professor Anderson, and it may be expected to have peculiar biological properties.

While the biochemist is busy probing the formula of the phosphosucride, other investigators are studying it biologically at the Rockefeller Institute for Medical Research, to determine to what extent the destructive powers of the tubercle bacillus are due to this element in its

make-up, and whether once identified, it will be of service in the treatment or prevention of the disease.

Other chemists in an analogous way have obtained specific chemical compounds from pneumonia bacteria, which show promise when applied clinically.

THE EUROPEAN FISH TAPEWORM. THE dangerous fish tapeworm of Europe, the largest of the parasites that commonly attack human beings, has become established in the United States, and is to be the object of special study this summer by a group of investigators backed by the National Research Council and under the immediate direction of Professor H. B. Ward, of the University of Illinois, foremost authority on internal parasites. They will go to the extreme northern part of Minnesota, which is the center of the