Historic Pictures

At top and bottom of this page are the first clear portrait ever made of individual molecules and the first detailed glimpse of a chemical reaction. Shown privately last fortnight before the American Philosophical Society (TIME, May 5), these pictures appear this week in public for the first time--released in the Journal of Biological Chemistry by Wendell Meredith Stanley and Thomas F. Anderson of the Rockefeller Institute for Medical Research at Princeton. The huge, self-reproducing molecules here pictured are the cause of the mosaic disease of tobacco plants -- viruses similar to those which cause such human ills as smallpox, influenza, infantile paralysis.

The pictures were taken with an electron microscope developed by R.C.A. (TIME, Oct. 28). The photographic plates were exposed by beams of electrons instead of beams of light. Practical limit of light magnification is about 2,000 diameters, of electron beams 100,000. These molecules are about ten-millionths of an inch long. In the picture above they are shown alone; in the picture below, they look fuzzy and out of focus because they are clustered over with antibodies, smaller molecules which produce immunity in organisms by reacting with the larger virulent ones. It is an action shot of a battle between the forces of disease and the forces of health.

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