The early work was undertaken at the plant of the American Synthetic Color Company at Stamford, Connecticut. Later a large plant was constructed at Edgewood Arsenal. At the latter place ten stills, 8 by 18 feet, were erected, together with the necessary accessory equipment. The following method of operation was used: The bleach is mixed with water and stirred until a cream is formed. This cream is then pumped into the still along with a solution of calcium picrate (picric acid neutralized with lime). When the current of live steam is admitted at the bottom of the still, the temperature gradually rises, until at 85° C. the reaction begins. The chloropicrin passes over with the steam and is condensed. Upon standing, the chloropicrin settles out, and may be drawn off and is then ready for filling into the shell. The yield was about 1.6 times the weight of picric acid used. PROPERTIES Chloropicrin is a colorless oil, which is insoluble in water, and which can be removed from the reaction by distillation with steam. It boils at 112° C. and will solidify at -69° C. At room temperature it has a density of 1.69 and is thus higher than chloroform (1.5) or carbon tetrachloride (1.59). At room temperature it has a vapor pressure of 24 mm. of mercury. It thus lies, in persistency, between such gases as phosgene on the one hand, and mustard gas on the other, but so much closer to phosgene that it is placed in the phosgene group. Chloropicrin is a very stable compound and is not decomposed by water, acids or dilute alkalies. The reaction with potassium or sodium sulfite, in which all the chlorine is found as potassium or sodium chloride, has been used as an analytical method for its quantitative determination. The qualitative test usually used consists in passing the gas-air mixture through a heated quartz tube, which liberates free chlorine. The chlorine may be detected by passing through a potassium iodide solution containing starch, or by the use of a heated copper wire gauze, when the characteristic green color is obtained.