as it had an unusual smell which some compared to the effluvia of marshy ground, M. Sérullas analyzed it, and after him MM. Boullay and Delens; and both analyses indicated the presence of a hundredth of its weight of hydriodate of soda, besides a little free iodine.[1] Subsequently, in reference to the discovery of arsenic by other chemists in different samples of suspected salt, M. Sérullas repeated his analysis, but could detect none of that poison.[2] Still more lately the whole subject has been investigated with great care by M. Chevallier.[3] M. Barruel states that he observed the occasional adulteration of salt with some hydriodate accidentally in 1824, while preparing experiments for Professor Orfila's lectures. He found it in two samples from different grocers' shops in Paris.[4] No satisfactory explanation has yet been given of the source of the adulteration with arsenic; but the presence of hydriodate of soda has been traced to the fraudulent use of impure salt from kelp [see p. 160].
Some difference of opinion prevails among toxicologists in regard to the alleged deleterious qualities of alum. On the whole it scarcely appears so active as to deserve the name of a poison; yet, like other salts, it may in large doses do serious injury. It merits particular mention among the present description of substances, partly on account of a trial at Paris, where dangerous effects were alleged to have been produced by it, and partly for the physiological inquiries made on that occasion. A druggist supplied a lady by mistake with powder of burnt alum instead of gum-arabic; and the lady, who had long laboured under chronic derangement of the stomach and bowels, took a single dose of a solution containing between ten and twenty grains of the salt. She immediately complained of acute pain in the stomach and gullet, burning in the mouth, and nausea; the symptoms of a severe attack of inflammation in the stomach and bowels ensued; and she was not considered out of danger for several days. The druggist was accordingly prosecuted, and heavy damages claimed. The attending physician ascribed the symptoms to the alum. But Marc and Orfila, who were consulted, declared that this was impossible except on the supposition that the lady had a very unusual sensibility of the stomach to irritating substances;—that it was a common thing to give three, four, and even five times the quantity in the treatment of diseases, without any such consequences resulting;—and that at the very time of the inquiry a physician in Paris was using it to the amount of six or eight drachms in a day. From an experimental inquiry conducted by Professor Orfila it appears, that large doses of calcined alum, such as one or even two ounces, excite in dogs little more than one or two attacks of vomiting, even although retained between ten and thirty minutes,—that one ounce will not excite any marked symptoms though secured in the stomach by a ligature,—but that two ounces given in the same way prove fatal in five hours, under symptoms of
