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]