Treatise on Poisons by Sir Robert Christison

emanations from fuel, and cause peculiar symptoms. But they are less apt to lead to accidents than the vapour of charcoal, as they are much more irritating to the lungs. This effect depends on the sulphurous acid gas which is mingled with the carbonic acid. Sulphurous acid gas is exceedingly deleterious to vegetable life, being hardly inferior in that respect to hydrochloric acid. Dr. Turner and I found that a fifth of a cubic inch diluted with ten thousand times its volume of air destroyed all the leaves of various plants in forty-eight hours.[2090] I am not acquainted with any experiments on animals or observations on man regarding the effects of the pure gas. But it will without a doubt prove a powerful irritant. Some of the peculiarities in the cases now to be mentioned were possibly owing to the admixture of sulphuric acid gas with the carbonic, both being inhaled in a diluted state. The cases are described by Mr. Braid, at the time surgeon at Leadhills. In March, 1817, several of the miners there were violently affected, and some killed, in consequence, it was supposed, of the smoke of one of the steam-engines having escaped into the way-gates, and contaminated the air in the workings. Four men who attempted to force their way through this air into the workings below were unable to advance beyond, and seem to have died immediately. The rest attempted to descend two hours after, but were suddenly stopped by the contaminated air. As soon as they reached it, although their lights burnt tolerably well, they felt difficulty in breathing, and were then seized with violent pain and beating in the head, giddiness and ringing in the ears, followed by vomiting, palpitation and anxiety, weakness of the limbs and pains above the knees, and finally with loss of recollection. Some of them made their escape, but others remained till the air was so far purified that their companions could descend to their aid. When Mr. Braid first saw them, some were running about frantic and furious, striking all who came in their way,—some ran off terrified whenever any one approached them,—some were singing,—some praying,—others lying listless and insensible. Many of them retched and vomited. In some the pulse was quick, in others slow, in many irregular, and in all feeble. All who could describe their complaints had violent headache, some of them tenesmus, and a few diarrhœa. In a few days all recovered except the first four and three others who had descended to the deeper parts of the mine.[2091]—Another accident of the same nature, and followed by the same phenomena, happened more lately at Leadhills.[2092] Similar accidents have been also witnessed by Mr. Bald, civil engineer, among the coal-miners who work in the neighbourhood of a burning mine belonging to the Devon Company. It is worthy of remark, that the men sometimes worked for a considerable length of time before they were taken ill. Such being the case, it will be readily conceived that the burning of the lights was not a test of the wholesomeness of the air. Here, as at Leadhills and in other instances already mentioned, the lights continued to burn where the men were poisoned.[2093]