A Look at a Molecule

The first clear picture ever made of a molecule was last week shown on a lantern slide. Some of the ablest U.S. scientists--members of the American Philosophical Society, founded 198 years ago by Benjamin Franklin--gaped in awe, for they were seeing something never before distinctly seen by man.

The slide was shown by Wendell Meredith Stanley of the Rockefeller Institute for Medical Research to the annual meeting of the Society in Philadelphia. It was a picture of the virus which causes the mosaic disease of tobacco plants, one of the largest molecules known to chemists. It is a rod-shaped structure, about 40,000,000 times the size of the hydrogen atom (basic unit of atomic and molecular weight). But even at this size it could be photographed only with the recently developed electron microscope (TIME, Oct. 28), which by using electron beams instead of light can magnify images 50 times greater than the best light microscopes.

Stanley and Thomas F. Anderson of R.C.A., who did the micrography, also showed a picture of a tobacco mosaic molecule about to be destroyed by an encircling legion of antibodies manufactured in the bodies of rabbits in which the virus had been injected. The pictures confirmed Stanley's theoretical reckoning that this molecule is about 20-millionths of an inch long and three-fifths of a millionth of an inch in diameter.

Scientists long knew that viruses caused smallpox, influenza, yellow fever, infantile paralysis, many other human, animal and plant diseases. But since they could neither see nor filter out viruses, scientists assumed that they were living, submicroscopic organisms. In 1935 Stanley showed that a pure strain of virus could be crystallized--consisted of lifeless molecules with the curious, lifelike power of reproducing themselves. This discovery closed the mysterious gap between living and inert matter, indicated no essential distinction except relative complexity of structure between atom, molecule, virus, cell and multicellular organism such as man.

Last week Dr. Stanley also reviewed his recent efforts to find which segments of the huge molecules are responsible for their virulent nature. Subjecting the molecules to chemical changes, he has produced new virus strains, thus in effect creating a new disease. Perhaps fortunately, the new-viruses so far revert to their original form in the second generation. But Dr. Stanley cheerily told his colleagues that he may yet invent some new disease.

Other notable discoveries reported at the meeting:

Carolina Craters. Like the moon, the coastal plain of South Carolina and nearby States is pocked with countless craters. The natives call them "bays," perhaps be cause bay trees grow among the pine forests which often cover the swampy depressions, making them scarcely noticeable--they can be seen clearly only from the air. The craters are usually rimmed with sand, oval in shape, parallel and varying from a few hundred yards to three miles in longest diameter.

Some geologists have believed that "a great cluster of giant meteorites, moving from northwest to southeast and striking the earth at an oblique angle, scooped out the numerous oval craters." This obvious, horse-sense theory was last week attacked if not demolished by Geologist Douglas Johnson of Columbia University. First he found two big flaws in it: 1) only meteorites a mile across could make some of these craters, whereas none larger than 20 feet across are known to have reached the earth; 2) though small exploding meteorites can make large craters, their holes are always circular, never oval, regardless of angle of impact, whereas most of the Carolina craters are oval (see cut).

So Professor Johnson conceived the idea that the craters might once have been made by huge artesian springs now dried up. Long ago, when the Atlantic Coastal Plain first rose above sea level, there was as yet no surface drainage system to tap underground waters. Instead, the water bubbled up through the sandy soil. To test his theory, Professor Johnson re-explored the Carolina craters and found startling confirmation: old wave marks and runoff channels which geologists never noticed while they were blinded by a false hypothesis.

Oldest Literature. From the late Stone Age to 2000 B.C., a non-Semitic people, the Sumerians, dominated the Euphrates Valley, the great "cradle of civilization." Even their name was lost to history until 1869, and not until recently has their literature been discovered and translated. This is the work of Samuel N. Kramer of the University of Pennsylvania Museum and the University of Chicago's Oriental Institute, who spent five years in museums at Istanbul and Philadelphia, copying crumbling clay tablets which had been ignored since their excavation nearly 50 years ago.

This "oldest written literature of significant quantity ever uncovered" consists of epics, myths, hymns, proverbs. Before the Society, Kramer read a poem, "Inanna's Descent to the Nether World," oldest known version of the universally significant myth of a descent into Hades. This myth, hitherto thought to be Semitic in origin, was taken over by all succeeding civilizations from the Assyrian to the Christian. Still more important, Kramer hopes, will be his translation of Sumerian "forerunners of the ancient myths concerned with the dying god and his resurrection, a group ... of basic significance for a scientific approach to the history of religion."

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