VOL.8. NO. 7
SEVENTH CENSUS OF RESEARCH STUDENTS
1375
It should be mentioned that in Table 11, while a column is given to the faculty, the numbers given there are not included in the totals, as those numbers refer to the graduate students only, and are comparable with the totals for previous years. It is hoped that this compilation may be continued until data are available for ten years, a t which time an effort may be made to evaluate the statistics, and to interpret the trend in the various fields of chemistry as well as in the universities in which the research is being done.
Atmosphere Influences Life of Books. The right atmosphere is necessary for the health of books as well as of humans. Too much heat, certain gases, dust, and improper lighting all tend t o shorten the lives of volumes on library shelves, recent studies conducted a t the Bureau of Standards of the U. S. Department of Commerce have shown. Cabinets in which the atmospheric conditions can he varied a t will are being used in the experiments. Preliminary findings indicate that the drying out effect of heat is an important cause of the aging of paper. Harmful effects of sulfur gases on paper are now being measured. It is thought that sulfur dioxide of the air is readilv absorbed bv . paper ~ and . chanaed . bv . chemical reaction to sulfuric acid which hastens the process of decomposition. Sulfur dioxide in the air has been found to be an important factor in the sudden deterioration of clothing in laundries in some communities where industrial plants involve the burning of quantities of soft coal. That sulfur gases may have a similar damaging effect on books in city libraries is suggested by the fact that the sulfur pollution in some industrial centers is known to be equivalent to a downpour of 100 tons or more of sulfuric acid per square mile. As a means of lengthening the life span of hooks and documents, the government investigators foresee a day when libraries will scientifically control the atmosphere surrounding their shelves. Regulating the heat and humidity, removing the dust and , minimizing the chemically acid impurities from the air circulated in the l i b r a ~and active light rays permitted to shine on the shelves are suggested improvements for the future.-Science Serwice New Unit of Atom Needed by Science. Scientists are now on the hunt for a new basic unit weight of matter. Chemists have in the past used the atom of oxygen as the unit of atomic weight, calling it 16. Dr. F. W. Aston of Trinity College, Cambridge, in a communication to scientists minted in Nature, has raised the point t h a t since there are now three known varieties of oxygen atoms, known as isotopes 16, 17, and 18. the actual weight of theaverageatomic weieht is about 1.25 parts in 10.000 =eater than the customary 16 - of the element oxyaen assumed in chemical books. While chemists might get along with the present standard, Dr. Aston intimates, physicists who compared the weights of individual atoms by means of the mass-spectrograph with an accuracy of 1 in 10,000, need a new and more definite unit. Among the possihle units suggested are: the proton or positive nucleus of the hydrogen atom, the neutral hydrogen atom, one-quarter of the neutral helium atom, onesixteenth of neutral oxygen atom 16. But none of these proposed units is entirely free irom obiection.-Science Seriice ~
