Similar accidents have occurred in cleaning out the Gay-Lussac towers. Such poisonings have repeatedly occurred in Germany. Fatal poisoning is recorded in the report of the Union of Chemical Industry, in the emptying and cleaning of a Gay-Lussac tower despite careful precautions. The tower, filled with coke, had been previously well washed with water, and during the operation of emptying, air had been constantly blown through by means of a Körting’s injector. The affected worker had been in the tower about an hour; two hours later symptoms of poisoning set in which proved fatal in an hour despite immediate medical attention. As such accidents kept on recurring, the Union of Chemical Industry drew up special precautions to be adopted in the emptying of these towers, which are printed in Part III. Naturally, in all these cases it is difficult to say exactly which of the acid gases arising in the production of sulphuric acid was responsible for the poisoning. In the fatal cases cited, probably nitrous fumes played the more important part. Poisoning has occurred in the transport of sulphuric acid. In some of the cases, at all events, gaseous impurities, especially arseniuretted hydrogen, were present. Thus, in the reports of the German Union of Chemical Industry for the year 1901, a worker succumbed through inhalation of poisonous gases in cleaning out a tank waggon for the transport of sulphuric acid. The tank was cleaned of the adhering mud, as had been the custom for years, by a man who climbed into it. No injurious effects had been noted previously at the work, and no further precautions were taken than that one worker relieved another at short intervals, and the work was carried on under supervision. On the occasion in question, however, there was an unusually large quantity of deposit, although the quality of the sulphuric acid was the same, and work had to be continued longer. The worker who remained longest in the tank became ill on his way home and died in hospital the following day; the other workers were only slightly affected. The sulphuric acid used by the firm in question immediately before the accident came from a newly built factory in which anhydrous sulphuric acid had been prepared by a special process. The acid was Glover acid, and it is possible that selenium and arsenic compounds were present in the residues. Arseniuretted hydrogen might have been generated in digging up the mud. Two similar fatalities are described in the report of the same Union for the year 1905. They happened similarly in cleaning out a sulphuric acid tank waggon, and in them the arsenic in the acid was the cause. Preliminary swilling out with water diluted the remainder of the sulphuric acid, but, nevertheless, it acted on the iron of the container. Generation of hydrogen gas is the condition for the reduction of the arsenious acid present in sulphuric acid with formation of arseniuretted hydrogen. In portions of the viscera arsenic was found.