CHLOROPICRIN, product of the distillation of bleaching powder with many nitro-compounds (e.g., picric acid, nitrometh ane) also prepared by the action of concentrated nitric acid on chloral or chloroform. A. W. von Hofmann (1866) mixed ten parts of bleaching powder into a paste with cold water adding a solution (saturated at 3o° C) of one part of picric acid. A vio lent reaction occurs and chloropicrin (nitrochloroform, trichloro nitromethane), distils over, generally without external heating. It is a colourless liquid of boiling-point 112°C, and of specific gravity 1.692. It is almost insoluble in water, but is readily soluble in alcohol ; it has a sharp smell, and its vapour powerfully affects the eyes. Chloropicrin has been employed in chemical warfare (q.v.) as a lachrymatory, irritant and lethal agent. High concentrations of this chemical cause fatal lung in juries and death may ensue from exposure to its action even at low concentrations.