VOL. 5, No. 1
HONORS P R O B LIN~ QUANTITATIVE ANALYSIS
95
students for the chance to do a second honors problem. The student acquires experience in explaining his problem to his fellow students, who, in their turn, see many processes used which are unusual in the regular course. And, after all, when a student has made a study of textbooks, references, and current literature, has made a decision as to the method he intends to follow, and then carries out his task successfully, has he not passed a worthy examination?
Cathode Rays Make Burns Like Those of X-Rays. Injuries caused by csthode rays, streams of electrons projected from Dr. W. D. Coolidge's recently invented tube. closely resemble bums due t o overdoses of x-rays and are similarly stubborn about healing. This is indicated by experiments performed by Dr. Victor C. Jacobson and Dr. Kenneth C. Waddell of the Albany Medical College, t o be announced soon in the scientific journal, Archives of Pathology. Rats were used as subjects of the experiments. The animals were wrapoed in .. jackets of copper foil t o protect them from being rayed all over, and only a spat ahaut an inch in diameter on the upper abdomen was left exposed. They were left in front - of the window of the apparatus for periods varying from one-tenth of a second t o six seconds daily for fourteen days, while others received only single rayings of from six seconds to a minute. Current was fed into the tube a t three voltages, 100,OW, 200,000, and 300,000 volts. respectively. The first sign of effect hy the cathode rays was in the change of hair color, from white to yellow. Then the skin appeared t o be tender, and finally developed pronounced sores, which were very slow t o heal. When the rats were chloroformed and the skin subjected to microscopic examination, the details of the damage resembled closely those of x-ray bums. The experimenters state that i t now appears highly likely that x-ray bums are really due t o cathode rays generated by the impact of x-rays on solid or lisuid objects which they encounter.-Science Service Light as Length standard Internationally Adopted. After years of painstaking scientific research an authoritative international agreement has been reached involving a single temperature scale, a fundamental standard of length, and a consensus of opinion concerning the basis of the world's electrical units. The agreement took place a t the Seventh International Conference on Weights and Measures. held recently a t Paris, the United States being represented by George K. Burgess, Director of the Bureau of Standards. The conference just held was the mast important in point of results secured since the first international gathering of the sort in 1875. While the meter and kilogram have received wide general recognition, their recognition as final standards did not occur until the m a t nations placed their approval on .. them a t this Fall's meeting. of the United States to define the length of the international The .proposition . meter in terms of the waw-length of the red radiation from the cadmium lamp was also tentatively adopted, the final wording of the recommendation as decided on by the conference being an improvement on that submitted by the United States. Thus there is established a permanent natural standard of length, easily reproduced and capable of being used in the most precise measurements. The relationship between the international meter and the wave-length of red light from cadmium vapor is: one meter equals 1.533.164.13 wave-lengths-SSciece Service
