stirred up that would never appear under ordinary cramming of f a c t s or would be diverted into other fields. The killing of enthusiasm in sophomore s t u d e n t s through the prospect of four or five long years of preparation f o r scientific work is one of the m o s t regrettable things in our present system of college education. An attempt to free the student and to let him think and work on his own seems to promise results that will more than pay for the t i m e t a k e n from the cramming of facts. We have f o u n d the course outlined above satisfactory f o r the teaching of chemistry to second-year students of the subject and we feel that in addition to the chemistry learned the students have been benefited by introduction to a number of things that were not formerly incorporated in second-year college chemistry.
Copper Makes Muck Land Bear Big Lettuce Crops. What is one plant's poison is another plant's medicine. Capper, long regarded as an element not friendly to plant growth, has been used to increase the productivity of certain muck lands used for vegetable growing in western New York, E. I,. Felix of Cornell University told members of the American Phytopathological Society recently. "The pro due ti^ and unproductive muck look just alike and no biological, physical or chemical differenrrs have been found between them, except in the response to copper treatment," Mr. Felix said. "With capper, lettuce and onions grow normally; without it they do little or nothing. Growers have applied the term 'rabbit ears' to affected lettuce because of the resemblance of the pale, upright narrow leaves to the ears of a rabbit, and the unrrroductive muck is known as 'rabbit ear muck.' 100 to 200 pounds of pulverized copper sulfate crystals prevented the occurrence of unproductive muck symptoms. Dusting or spraying affected lettuce ~. with small quantities of copper sulfate caused the plant; already affected to become healthy in appearance."-Science Service Atoms Act Like Billiard Balls on Tungsten Pool Tables. Whenan atom of cesium, 8 metallicelement in the same group as sodium and potassium, hits a surface of hot tungsten, such ar the glowing filament of a tungsten electric lamp, it doesn't bounce off a t once, but rolls around for a distance equal to a million times its awn diameter. This was related a t the meeting of the American Physical Society hy Dr. Joseph A. Becker, of the Bell Telephone Laboratories. But if a cesium atom hits a surface of cesium instead of tungsten, it is bumped right off again. Radio vacuum tubes with filaments coated with cesium have been found to have an advantage over uncoated filaments. Dr. Becker learned these facts in a study of the way in which cesium is "adsorbed" on a tungsten filament. When this process takes place, a layer of cesium atoms is formed on the surface of the tungsten.wire. In a second, a layer one atom deep is formed on the wire, and then a point is reached where the cesium atoms evaporate from the wire as fast as atoms are adsorbed. He has found, Dr. Becker said. that the average life of one of these atoms on the surface of the filament varies with temperature. At a temperature of 645 degrees Fahrenheit, theatom sticks for a hundred seconds, while a t 730 degrees it sticks for only a second.-Science Service
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