Further study by the National Carbon Co., backed up by wonderful large-scale development work, paid for and carried out by the National Electric Lamp Association under the direction of their Mr. F. N. Dorsey (who later became Col. Dorsey and chief of the Development Division of the Chemical Warfare Service), gave us the details of a new process for treating the charcoal to make it absorptive. After the original burning of the nut shells, or other carbon materials, the resulting carbon was given a second highly specialized heat treatment, and this activated it until it had a powerful affinity for gas. Such carbon, made from nutshell material, would absorb 150 times its own volume of chlorpicrin, one of the most deadly of the war gases, the action being approximately instantaneous.
It must not be supposed, however, that investigation of carbons stopped with these experiments. In the search for the ideal carbon we experimented with almost every hard vegetable substance known. Literally, hundreds of kinds of carbon were tested. Next to coconut shells, the fruit pits, several common varieties of nuts abundant in the United States, and several tropical nuts, were found to make the best carbon. Pecan nuts, and all woods ranging in hardness from ironwood down to ordinary pine and fir, were found to be in the second class of efficiency. Among other substances tested were almonds, Arabian acorns, grape seeds, Brazil-nut husks, balsa, osage oranges, Chinese velvet beans, synthetic carbons, cocoa bean shells, coffee grounds, flint corn, corn cobs, cottonseed husks, peanut shells and oil shale. While many of these substances might have been used in an emergency, none of them would produce carbon as efficient, volume for volume, as that of the coconut shells and other hard nuts.
Some idea of the scale of the American mask production may be seen in our requirements for coconut shells. In our survey of raw materials we included the entire coconut resources of the world. Such figures were relatively easy to obtain because the copra, or dried coconut meat, industry is an important one, particularly in southern Asia and the South Sea Islands of the Pacific. Ceylon was the greatest single source of coconuts, 2,300,000,000 nuts being gathered there annually. British India was next with 1,500,000,000 nuts. Our own Philippine Islands were third, with an annual production of 900,000,000 nuts. Then followed in order the Dutch East Indies, British Malaya, French Indo-China, Siam, and the Pacific archipelagos, the total production of the Orient being 7,450,200,000 nuts annually. This was a supply that would provide 4,000 tons of coconut shells every day. The total production of coconuts in Central America, the West Indies and the Caribbean coast of South America amounted to 131,000,000 nuts annually, equal to a supply of 75 tons of shells daily.
When we first began to build masks our demands for carboniferous material ranged from 40 to 50 tons a day of raw material; but by the end of the war, due to vastly increased mask requirements, we were in need of a supply of 400 tons of coconut shells per day. This demand would absorb the entire coconut production of the tropical Americas five times over. It was equal to one-tenth of the total coconut production of the Orient. Since transportation from the oriental countries was out of the question on the scale demanded by our mask program, it was evident that we were likely to be seriously embarrassed by the lack of raw materials; and, indeed, at no time before September, 1918, did we have on hand a reserve supply of shells and other charcoal materials that would last for more than a few days, though at no time after the start was the actual output of masks retarded by lack of these materials.
AIRPLANE PICTURE OF CARBON PLANT AND CANTONMENT OF GAS DEFENSE DIVISION AT ASTORIA, LONG ISLAND.
GENERAL VIEW OF CARBON PLANT NO. 3 ON LEFT AT GAS DEFENSE DIVISION PLANT, ASTORIA, L. I.
Storage bins are in central background, with administration building and carbon plant No. 2 in the right foreground.
