Finally about March 1, in accordance with the strong recommendations of these men, Fries reported to General Pershing in person that the manufacture of gas as well as the filling of shell in France was inadvisable from every point of view and accordingly he recommended that gas manufacture and shell filling in France be given up. General Pershing strongly approved the recommendation and a cablegram was at once sent to the United States to that effect. The main reason for this action was the lack of chlorine, since chlorine was the principal ingredient of nearly all poisonous gases then in use. Chlorine takes, besides salt, electric power and lots of it. Electric power requires coal or water power. Neither of the latter sources were available in France. This question was gone into very thoroughly. The only place where power might have been developed was in a remote spot near Spain, and the outlook there was such that it appeared impossible to begin the manufacture of chlorine under two years. On the other hand the shipment of chlorine from the United States required from 75 per cent to 100 per cent of the tonnage required to ship the manufactured gases themselves, to say nothing of the labor, raw materials, and the machinery that would have had to be shipped in order to manufacture gas in France. =Mustard Gas.= As previously stated Mustard Gas was first used by the Germans against the British at Ypres on the nights of July 11 and 12, 1917. It was not used much against the French until more than two months later. Indeed, gas was never used by the Germans to the same extent against the French as against the English. There are probably two reasons for this; first, the Germans had a deeper hatred for the British than the French; second, the British morale was higher than the French in 1917, and the German thought that if he could break down this British morale, he could win the war. The first attack came as a surprise and accordingly got an unusually large number of casualties. As previously stated the casualties numbered about 20,000 in about six weeks. This number was considered so serious that the beginning of the series of attacks against Ypres in the fall of 1917, was delayed by the British for 10 days or two weeks until they could study better how to avoid such great losses from mustard gas. While the composition of the gas was known within two or three days, as well as the laboratory method by which it was first manufactured by Victor Meyer in 1886, it took some 11 months to develop reliable and practical methods of manufacturing it on a large scale. The Inter-allied Gas Conference in September, 1917, gave a great deal of attention to mustard gas and methods of combating it both from the view point of prevention and of curing those gassed by it.