This gas is developed by several chemical processes. We have just stated that if, during the burning of charcoal, moisture be present, it is evolved in abundance. It appears to be particularly fatal to animal life. Dr. Beddoes made many experiments upon the subject, from which it would seem to destroy life by rendering the muscular fibre inirritable without producing any previous excitement. In order to decide this question, Sir Humphry Davy[505] ventured to take three inspirations of the gas produced from the decomposition of water by charcoal. “The first inspiration produced a sort of numbness and loss of feeling in the chest, and about the pectoral muscles; after the second,” says he, “I lost all power of perceiving external things, and had no distinct sensation, except a terrible oppression on the chest; during the third expiration, this feeling disappeared; I seemed sinking into annihilation, and had just power enough to drop the mouth-piece from my unclosed lips. There is every reason to believe, that if I had taken four or five inspirations, instead of three, they would have destroyed life immediately, without producing any painful sensation.”
This gas, which is now considered as an elementary body, has received from Sir Humphry Davy the name of chlorine, from the green colour which characterises it. Its odour is so penetrating and insupportable that it is impossible to respire it, even when considerably diluted with atmospheric air, and yet it will support combustion. It discharges vegetable colours, whence it forms the basis of various bleaching preparations. According to the experiments[506] of M. Nysten, this gas is not absorbed when respired pure, but appears to act only by irritating the bronchiæ locally; and so energetic is its action, that the animal dies before there is sufficient time for asphyxia to take place from the circulation of black blood. When it is respired in a dilute form, it produces a severe cough, and, according to Fourcroy, it occasions a phlegmonic inflammation of the bronchial membranes. The death of the ingenious and indefatigable Pelletier was occasioned by his accidentally inhaling a proportion of this gas; a consumption was the consequence, which in a short time proved fatal. In the London Medical and Physical Journal for November, 1821, a case of a person is recorded who was poisoned by bleaching liquor.
The gas is generated by the combustion of sulphur. It is colourless; has a pungent smell, resembling that of burning sulphur, and is very soluble in water. It would appear to destroy life by a peculiar action on the blood.