Savants in St. Louis

By last week the gap between living and nonliving things was so narrow as to be almost nonexistent. A century ago the demarcation between organic and inorganic matter was sharp. It grew hazy when chemists began to make com pounds artificially. They found that hydrocyanic acid, simply standing in water, gives rise to urea and other substances found in living tissues. Now that thousands of organic compounds have been synthesized, it is chemical custom to call "organic" any compound, however formed, that contains carbon, since carbon is a notable component of plants and animals. Lately Rockefeller Institute researchers have isolated in the form of crystals a virus which causes a plant disease called tobacco mosaic. The virus seems to consist of a protein molecule with a molecular weight of several million units. In most respects it is not alive; the crystal structure, for example, is typical of inanimate materials such as metal. But when it makes contact with plant tissue, the molecules at once acquire the ability to reproduce themselves--a prime prerequisite of life.

Facts of this sort were pointed out to the American Association for the Advancement of Science in St. Louis last week by Dr. Oscar Riddle, 58, crack geneticist of the Carnegie Institution of Washington, in an address entitled "The Confusion of Tongues." Dr. Riddle asserted that it was high time for science to carry evolution back not only to primordial organisms, but to their natural production from wholly inanimate substances. It has been learned that all that is necessary for the spontaneous generation of certain sugars is sunlight, colored surfaces, water, carbon dioxide, moderate temperatures. Such factors were undoubtedly present on earth a billion years ago. The gap between such naturally generated substances and the half-alive tobacco mosaic virus may be almost no gap at all. Other highlights of the St. Louis meeting (see p. 28).

Explosives. Extremely dangerous are the dynamite-caps or detonators used for blasting in mines. Last year a Baltimore woman, opening the door of a furnace, was struck in the breast by a copper pellet no bigger than a pinhead, which killed her. Investigation showed that the pellet had come from a detonator, no doubt left in the coal by a miner; that such detonators not only hurl a pellet at 6,000 ft. per sec. (three times the speed of a rifle bullet) but throw hundreds of minute shreds of copper, each able to penetrate nearly a millimetre of brass sheet. Pellets from detonators, directed into jars of water, shatter the jars by the pressure wave in the water. As evidence that modern high explosives are not to be tampered with, Dr. Robert Williams Wood of Johns Hopkins exhibited a lantern slide depicting the impression of an apple leaf driven into solid steel by guncotton, declared the detonation in a tube of nitroglycerin proceeds at four mi. per sec., described a new explosive, iodide of nitrogen, which is so skittish that the landing of a housefly sets it off.

Super-eye. Dr. Vladimir Kosma Zworykin of RCA Victor showed how his iconoscope developed for television and microscopy (TIME, July 10, 1933, March 5, 1934) can see in the dark. When he placed this foot-long glass tube in a motion-picture beam, a photosensitive grid in the front of the tube converted the light into a beam of electrons, which reproduced the moving images on a small fluorescent screen at the tube's back. When a black glass filter was interposed between the cinema projector and the iconoscope, all visible light was shut off. But the reproduction of images on the fluorescent screen continued--because of invisible ultraviolet light passing through the black filter.

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