acid gas; and that it acts with energy on animals, whether it be inhaled, or injected into the stomach, anus, or cellular tissue, or even simply applied to the skin. Nine quarts of the gas injected into the anus of a horse killed it in one minute; and a rabbit, whose skin alone was exposed to it, died in ten minutes.[1] Ulterior inquiries by MM. Parent-Duchâtelet and Gaultier de Claubry,—scarcely so precise however as those of their predecessors,—appear to lead to the conclusion, that its energy is in some circumstances not so great. While superintending the clearing out of some of the choked drains of Paris, they found that the workmen suffered no harm, though they habitually breathed an atmosphere containing from 25 to 80 ten-thousandths of hydrosulphuric acid gas, and on some occasions even so much as one per cent.; nay, on one occasion Gaultier remained several minutes without injury, collecting air for chemical analysis in an atmosphere, which proved to be loaded with three per cent. of the gas.[2] None of these researches point out the precise manner of death. Dr. Percy of Nottingham informs me he found in 1839, that dogs, which breathed air, containing this gas, quickly died in convulsions like those caused by hydrocyanic acid; that in some instances the heart's action was observed to have ceased, when the body was opened immediately after death; but that in general it either continued to beat for some time, or could be made to do so when its state of congestion was relieved by withdrawing a little blood.
Dr. Turner and I found that hydrosulphuric acid gas is very injurious to vegetables, and that it acts differently from muriatic acid gas, as it appeared to exhaust the vitality of plants and to cause in them a state analogous to narcotic poisoning in animals. Four cubic inches and a half, diluted with eighty volumes of air, caused drooping of the leaves of a mignonette plant in twenty-four hours; and the plant, though then removed into the open air, continued to droop till it bent over altogether and died.[3]
The best description of the effects of this gas on man has been given by M. Hallé,[4] in his account of the nature and effects of the exhalations from the pits of the Parisian necessaries; which exhalations appear, from the experiments of Thenard and Dupuytren, to be mixtures chiefly of ammonia and sulphuretted-hydrogen. The symptoms, in cases where the vapours are breathed in a state of concentration, are sudden weakness and all the signs of ordinary asphyxia. The individual becomes suddenly weak and insensible; falls down; and either expires immediately, or, if he is fortunate enough to be quickly extricated, he may revive in no long time, the belly remaining tense and full for an hour or upwards, and recovery being preceded by vomiting and hawking of bloody froth.[5] When the
