It is a remarkable commentary on the efficiency of the Edgewood organization that notwithstanding the fact that the manufacture of poison-gases in quantity was a new industry in the United States, that the machinery was improvised or designed from the ground up, that the workmen were without previous experience—many of the drafted men, mind you, were fresh from offices, stores, and farms—and that they were engaged in a peculiarly hazardous occupation, only four fatalities were directly traceable to poisoning by gas. This should not be construed as minimizing the peril attached to the work, however, for, though every possible precaution was observed in the construction and operation of the plants, there were 925 casualties between June and December, 1918, of which 674 were due to mustard-gas. During the month of August, when the gases were most volatile as a result of the excessive heat (during that month the mercury stood at 106 degrees for three days in succession), and when the weather caused the soldiers to somewhat relax their precautions, the hospitals were on several days filled at the rate of 3½ per cent of the entire force of the mustard-gas plant, though this rate of casualties was not maintained, of course, throughout the entire month. I might add that several of the divisions which took part in the St. Mihiel offensive sustained a considerably smaller percentage of losses, which shows that the dangers of the war were not entirely monopolized by the men who served in France.