VOL. 6, No. 1
ABSTRACTS
171
I n pure science the psychologist, J. McKeen Cattell, states: "It is my general impression that the United States is in advance of Great Britain and Germany in the biological and geological sciences and in astronomy, behind them in physics, chemistry, and physiology, and about an even terms with them in mathematics." Professor Joseph Mayer of Tufts College, in the January Scientific Monthly, states: "In the lmt hundred years the United States, France, Great Britain, and Germany have each produced more than thirty outstanding scientists, while no other country has produced mare than six." T. B. D. Something for Nothing. WnLlaM HOSKINS. Am. Mag., 106,43 (Nov., 1928).William Hoskins, a distinguished chemist tells, in this interview, how scientific fakers have cashed in on the credulity of people who hope for quick riches. Numerous and various illustrative examples are given. Advice is given t o those who are planning on making an investment in some scientific scheme. E. L. M.
Measuring Atomic Layers Step to Better "Talkies." Layers of metallic rubidium, only one atom deep, so thin that several million would be required t o equal the thickness of the paper this is printed on, have been measured a t the Bell Telephone Laboratories in New York. Thin films of rubidium, a metal similar t o the sodium of common salt, are important because of their use in photoelectric cells. As the magic lamp of modern physics, the photoelectric cell, transmuter of light variations into sound. is the very heart of the revolutions in industry that have been plotted in the physics laboratories. Talking motion pictures, radiovision, television, telephoned photographs would all be impossible without the photoelectric cell. I n the course of researches on how t o make the photoelectric cell most efficient, the thin films. When the thin f l m of metal inside the glass A. L. Johnsrud me-d cell was very thin it operated better than when thicker. Rubidium can be made into thin flms more easily than its relative metals, because a t rather low temperatures and without.10~~ of time i t can be made t o evaporate and the vapor deposited, in a vacuum, t o form such a film. A large photoelectric cell was made and so arranged that rubidium could gradually be deposited on the glass, or else, after a thick deposit had been made, it could gradually be removed. While the film was thus getting thicker a thinner, the photoelectric response, the nurent given off when light fell on it, could be measured. Since the maximum response was obtained a t the same point, whether the film was growing thicker or thinner, it was necessary exactly t o record the film's depth. Ordinary measuring methods proved inadequate and polarized light was used. Polarized light differs from ordinary light because, by passage through a special kind of prism, i t is made t o vibrate in a single direction. Ordinary light waves vibrate up and down, right and left, and in every conceivable direction, but that of polarized light is confined t o a single plane. When polarized light passes through any flm, such as the one of rubidium, the direction in which i t vibrates is twisted. The thicker the film, the more it is twisted. By means of another prism similar t o that which polarizes the Light the extent of the twisting, and also the thickness of the film, is measured. The most current was obtained when the film was but one atom thick.-Science Service Chemist Finds New W a y t o h e s e m e Ether. Ether, which is widely used as an anesthetic during operations, may now he stored for as long as eight months without spoiling or deteriorating, S. Palkin and H. R. Watkins reported a t the Swampscott meeting of the American Chemical Society. This valuable substance, which has made possible the triumphs of modem surgery, does not keep well in the pure state. The two chemists have found a way to preserve ether without making i t Less pure, using either of two preservative agents, pyragallol or permanganate, which do not in any way atfed the other properties of ether.-Science Service
