Science: Canaries & Ferryboats

Live canaries, which used to be carried down into coal mines as sentinels against firedamp, are not often stationed in modern chemical laboratories. Nevertheless, Dr. Harold Clayton Urey and his coworkers* at Columbia University have kept canaries within sniffing distance of their apparatus for months. Reason: the chemists were working with two deadly poisons, hydrogen cyanide (used in some U. S. States to execute condemned criminals) and sodium cyanide. If these began to leak from the apparatus, the sensitive little birds would collapse in time for the men to take action. Pacific, round-faced, gum-chewing Dr. Urey and his associates were not interested in poison, they were simply using the dangerous gases to make a harmless but scientifically important substance called "heavy carbon." An atom of heavy carbon weighs 13 units as compared with ordinary carbon's twelve.

Atoms of the same chemical element which have different weights are called isotopes. Isotopes are Chemist Urey's special ty. He won a Nobel Prize for discovering deuterium, the heavy isotope of hydrogen which makes "heavy water" (TIME, Nov. 26, 1934). Later, one of the Urey crews produced large quantities of heavy nitrogen (TIME, Sept. 20, 1937). Nitrogen is present in all proteins. Heavy nitrogen atoms can be distinguished from the common kind by mass spectrographic means, but in protein reactions they run along with their lighter fellows, and so serve as "tagged atoms" or chemical spies to show where the nitrogen goes. Carbon is a vital ingredient of all living substance, and by using heavy carbon atoms as tracers Dr. Urey expects physiologists to find out much more about carbon metabolism than is now known.

The heavy carbon apparatus is a tall glass cylinder with glass spirals inside. Heavy carbon can be separated from light carbon because it dissolves in hydrogen cyanide and sodium cyanide at slightly different rates. When sodium cyanide in water solution runs down the spiral and hydrogen cyanide as a gas flows upward, heavy carbon collects at the top of the apparatus. There were no leaks and the canaries warbled serenely on.

Such was the experiment described by Dr. Urey last week at a convention of the American Chemical Society in Boston. Another highlight of the meeting:

Belgian-born Dr. George Calingaert (pronounced Kale-in-gert) of Ethyl Gasoline Corp. turned up with a discovery which sounded abstruse to laymen but which his colleagues hailed as "fundamental" and "revolutionary." The discovery: that certain closely related organic compounds will react with one another (i.e., form new compounds) when nudged by simple catalysts (chemical activators) at ordinary temperatures. Up to now chemists have regarded such compounds as indifferent to one another, capable at best of being shotgunned into chemical matrimony by violent stimulants, high temperatures and great pressures. These strongarm methods, even when successful, are wasteful. In the Calingaert process the new molecules slide together without fuss.

"The new reaction," said Dr. Calingaert, "all but shakes the foundations of our general concepts of the behavior of atoms in molecules."