[501]. Where mercury is sublimed, it will usually assume the appearance of a black powder, in consequence of the extreme state of division it has undergone. This appearance has no doubt deceived the superficial observer, and given origin to many erroneous statements.
[502]. “A small portion of mercury was put through a funnel into a clean dry bottle, capable of holding about six ounces, and formed a stratum at the bottom not one-eighth of an inch in thickness; particular care was taken that none of the mercury should adhere to the upper part of the inside of the bottle. A small piece of leaf-gold was then attached to the under part of the stopper of the bottle, so that when the stopper was put into its place, the leaf-gold was enclosed in the bottle. It was then set aside in a safe place, which happened to be both dark and cool, and left for between six weeks and two months. At the end of that time it was examined, and the leaf-gold was found whitened by a quantity of mercury, though every part of the bottle and mercury remained, apparently, just as before. This experiment has been repeated several times, and always with success. The utmost care was taken that mercury should not get to the gold, except by passing through the atmosphere of the bottle. I think therefore it proves that at common temperatures, and even when the air is present, mercury is always surrounded by an atmosphere of the same substance.”—On the vapour of mercury at common temperatures, by M. Faraday, Chemical Assistant at the Royal Institution. Journal of Science and the Arts, vol. 10, p. 354.
[503]. Mr. Plowman has since stated, in conversation, that he has seen five or six mice, in one day, come into the ward-room, leap up a considerable height, and fall down dead on the deck. He also stated that the food for the use of the canary bird was kept in well closed bottles, so that it was impossible for it to have contracted any metallic impregnation.
[504]. The gases given off by burning coal, will vary very much according to the activity of the combustion, and the degree of moisture present; so that we may expect to receive sulphuretted hydrogen, sulphurous acid, carbonic oxide, carbonic acid, and carburetted hydrogen.
[505]. Researches Chemical and Philosophical, chiefly concerning nitrous oxide, &c. London, 1800.
[506]. Recherches de Physiologie et de chimie, p. 144, an. 1811.
[507]. See the case in Valentini, P. M. L. p. 538, of a woman wilfully killed by continual and excessive doses of sulphuric acid, administered to her under pretence of medicine.
[508]. See the trial of Jane Butterfield for the murder of Wm. Scawen, Esq. published from the short hand writer’s notes, London 1775. Miss Butterfield was acquitted, the case is therefore put supposititiously.
[509]. Such was the case of the ignorant man who went out at night with the intention of shooting a ghost, which was supposed to haunt the village of Hammersmith; he actually shot a bricklayer’s labourer who was returning from his work; this was held to be murder, and the prisoner was convicted; he was not indeed a fit subject for execution, and was therefore pardoned; but this should not be extended into a doctrine, that gross ignorance, producing death, is always a pardonable offence.
Transcriber’s Note