Smaller & Smaller

For men's deepest thrust into the infinitesimal, he can thank a microscope that sees things without the help of light. This is the electron microscope. With it, in Camden, N. J., Berlin, London, Toronto and Pasadena last week, scientists studied things 50 times smaller than they could see a decade ago.

With microscopes using visible or ultraviolet light, magnifications of a sort up to 5,000 diameters have been obtained, but the really useful upper limit has hovered around 2,000 diameters. With microscopes using electron beams, useful magnifications have jumped to 100,000 diameters and more. Light is a train of waves; to pick some tiny body out of the unseen, the waves must find it big enough to get hold of. If the body is much smaller than the wave length, it will slip through like a mosquito through a fishing net. Electron beams are also wave trains, but their wave lengths are thousands of times shorter than those of light. So, in effect, they give scientists a collecting net of far finer mesh.

High electronic magnifications (105,000 diameters) of vinylchloride polymer, a rubberlike synthetic, show a mottling of dots which scientists assume to be actual molecules; 25,000-diameter pictures of soft face-powder granules reveal the jagged projections which make them cling to the skin. Electron photographs of typhoid germs and intestinal bacteria disclose delicate, wavy filaments which may be their means of locomotion.

Anthrax bacilli are seen to be joined at the ends by curious disklike couplings. Strings of streptococci are held together by outer membranes which look like sausage casings.

Two great pioneers in electron microscopy are the German firm of Siemens & Halske (TIME, June 6, 1938), and, in the U. S., the R. C. A. laboratories at Camden (TIME, Jan. 9, 1939). R. C. A.'s big man in the field is Russian-born, reticent Vladimir Kosma Zworykin, who is also its television ace. His first electron microscope was as big as a hot-water boiler, needed a whole roomful of high-voltage equipment to run. Since then R. C. A. has designed a smaller, slimmer, slicker instrument, whose power plant occupies only two cubic feet. R. C. A. says that any bright person can learn to get good results with it in an hour. Last week R. C. A. was ready to market the new model to research institutions. Price: $9,500 an instrument.

Some of the high-magnification details of disease germs are too new to be of anything more than academic interest. But eventually, if science follows its historic course, they will be put to use. Probably scientists will soon make visible the viruses, mysterious disease agents small enough to pass through porcelain filters.* They may uncover the genes (unit heredity carriers) in their hiding places along the chromosomes of germ cells. By ultra-high magnifications of cancerous cells, they may shed the ultimate light on the cause of malignant tumors.

*A recent report from Berlin alleged that the smallpox virus had been seen there for the first time.

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