“PREPARATION OF ETHYLENE CHLORHYDRIN—The reaction was carried out in a cylindrical tank resting on its side. The tank was furnished with a stirrer and was insulated by means of cork in order to prevent the transfer of heat from the atmosphere to the inside. Enough chloride of lime was introduced into the tank to furnish 500 kg. of available chlorine, together with 5 cu. m. of water. At first, about 20 cu. m. of carbon dioxide were led into the mixture, next ethylene, and later carbon dioxide and ethylene simultaneously. The rate of absorption of ethylene was noted and when it slackened, more carbon dioxide was added. Fuller details as to the addition of the two gases were not given as it was stated that it was a matter of judgment on the part of the workman who was carrying out the operation. The reaction should be carried out at as low a temperature as possible, but it was found impossible to work below 5° with the apparatus employed in this factory. The temperature during the reaction varied between 5° and 10°. In order to maintain this temperature, the solution was constantly pumped from the apparatus through a coil which was cooled by brine. When ethylene was no longer absorbed and there was an excess of carbon dioxide present, the solution was tested for hypochlorous acid. The time required for the introduction of ethylene was between 2 and 3 hrs. “The contents of the apparatus were passed through a filter press by means of which the calcium carbonate was removed. The solution thus obtained contained from 10 to 12 per cent of ethylene chlorhydrin. It was next distilled with steam and a distillate collected which contained between 18 and 20 per cent of chlorhydrin. The yield of chlorhydrin was from 60 to 80 per cent of that calculated from the ethylene used. [Illustration: FIG. 35.—Mustard Gas Manufacture at Leverkusen. Layout for Chlorination of Thiodiglycol.] “PREPARATION OF DIHYDROXYETHYLSULFIDE—To prepare the hydroxysulfide, the theoretical quantity of sodium sulfide, either in the form of the anhydrous salt or as crystals, was added to the 18 to 20 per cent solution of chlorhydrin. After the addition of the sulfide, the mixture was heated to about 90° to 100°. It was then pumped to an evaporator, and heated until all the water was driven off. The glycol was next filtered from the salt which separated, and distilled in a vacuum. The yield of glycol was about 90 per cent of the theoretical, calculated from the chlorhydrin.