1682
JOURNAL OF CHEMICAL EDUCATION
JULY.
1930
Table VIII) by the engineering and science and literature students, which group includes those majoring in chemistry and chemical engineering. Conclusions (1) It is clearly evident that there is a marked difference in the performance in chemistry by the students in the different schools and that engineering and science and literature students rank higher than the others. (2) Evidence is not sufficiently definite to place the other schools. (3) In preparation, as in performance, the engineers and science and literature students are best, whiie the agriculture and home economics students are the poorest. (4) Performance in college chemistry in this school appears to depend largely upon the aptitude of the students and their prior preparation in high and grade schools. Artificial Snowflakes. The first artificial snowflake ever made by man has been produced in Los Angeles, a city which almost never sees natural snow, by Prof. John Mead Adams, of the University of California's Los Angeles laboratory, and is reported by him to the American Physical Society. Ordinary methods of freezing samples of fog or of cooling water sprays or moist air do not produce snowflakes but only frost crystals, hailstones, or other bits of ice. How to form the beautiful lacy structure of snowflakes has been one of Nature's secret proceses, camed out only in the upper air. After ten years' work, Professor AdaPns has perfected an apparatus in which real snowRakes can be produced, although they are n+icroscopic in size, the largest measuring less than one-ten thousandth of an inch. A stream of cold dry gas from evaporating liquid air passes into a cold chamber also supplied with a stream of cold moist air only a degree or two above the freezing point of water, but hundreds of degrees warmer than the stream of dry gas from the liquid air. When the super-cold dry gas from the liquid air meets the cold hut moist stream of ordinary air, thousands of very tiny snowflakes are produced. Some of these can be caught on an illuminated glass plate and watched under a miaoscope. A part of them grow larger a t the expense of their smaller fellows, a cannibalistic process believed t o happen also in the upper air when natural snowflakes are produced.-Baltimore Sunday
Sun
Dead Sea Potash. I n an interview Dr. S. Van Vriesland said that it was first intended t o extract potash from the Dead Sea, then bromide, and eventually, when transport facilities are adequate, i t might he possible t o produce common salt on a commercial scale. At present transport was by road, and before the work could be fully developed a railway down the Jordan Valley would be needed. The salt water was run into shallow pans and left in the sun to evaporate, a method that will be used when the work is developed, but the pans a t present were for experimental purposes only. Dr. Novomeysky, who formed the company, had been working a t the Dead Sea for nearly 20 years, and recent tests had been extremely satisfactory. The potash would be used largely far fertilizer in Palestine.-Chcm. & Ind.
