[11] By means of a solar microscope, I have seen the animalcula in vinegar several inches in length, some of which had the appearance of eels, and in motion.
[12] There is a sort of mountebanks not only in Ceylon, but in many other parts of the East Indies, who make a trade of taming serpents, which they pretend to do by incantation, and carry them about by way of show. I once witnessed the taming of a serpent, a black snake about four feet in length, by an English gentleman at Harrowgate, in the neighbourhood of Philadelphia. He was remarkably fond of snakes for pets, and had them not only to follow him, but also to be about in the house among his children, who became familiar with them; and, although young myself, I observed that they were passive and obedient, and knew by instinct their dependence on his favours.
The incantation, that Mr. C—d used, was simply this: The snake was put into a room, and Mr. C. took in with him a bowl of milk, and the door was closed. Having taken off his coat, and put on a glove, he proceeded towards his antagonist, who, being prepared for the attack, made at him, but was repulsed; a second and third attempt was made, but he was thrown back as before. The snake finding himself mastered, did not think proper to renew the combat, and crawled into the corner panting for breath. Mr. C. now took some of the milk and placed it before him, without the least fear, and after he had finished it, he gave him more. This he continued until the snake was satisfied. After which, to the astonishment of all who witnessed the experiment, he took it up, and having wound itself round his arm, he carried it home. Whether he examined his mouth, destroyed the fang, or the vesicular sac, (if it had one), I do not recollect; but this same snake was afterwards a great favorite, and would follow his master like a dog, and even play about with the children. I mention this incident to show, that serpents possess considerable instinct, and are, like domestic animals, conscious of their friends and benefactors, and may be trained in the same manner.
In the island of Ceylon, there is a small animal called the Indian Ichneumon, which destroys snakes in abundance; but, what is remarkable, he only attacks them in an open place, where he has an opportunity of running to a certain herb, which he knows instinctively to be an antidote against the poison of the bite, if he should happen to receive one. The monkeys of India, knowing the malignity of snakes, make a business of hunting and destroying them at night; after seizing them, they carry them to a stone, and beat their heads until the fangs are destroyed, and then exultingly throw them in the air. The poison is lodged in two small vesicles, and when the animal bites they are squeezed, and the poison is forced through the fangs into the wound. If the vesicles be extracted, or the liquid prevented from flowing into the wound, the bite is harmless.
[13] The great cave on Crooked Creek, was discovered about the year 1800, by Mr. Baker. He proceeded only a small distance into it. On the succeeding day, he brought his wife, and two or three children to explore it. He carried a torch, which he accidentally dropped. During two days and two nights, this family wandered in total darkness, though sometimes within the hearing of a cataract, when, fortunately, Mrs. Baker, in attempting to support herself on a rock, perceived that it was wet. She conjectured that it was caused by the mud, which they had brought in upon their feet. Baker immediately ascended the rock, and saw the light of day.
[14] There can be no doubt, as we observed, that miasma is variously compounded; but there is no certainty, as to what it is composed of, or what modifications it may assume. That it is, however, a chemical combination, and may be decomposed, and destroyed by chemical agents, appears equally true. The disinfecting apparatus of Morveau, sundry fumigations, &c. are used for this purpose. The proper destroyers of these gaseous poisons, are nitric acid vapour, muriatic acid, and chlorine. The two last are the most effectual. How would chlorine gas act on prussine gas, or cyanogen? Would it not deprive it of its carbon, forming the chlorocarbonic acid, and thus set the azote at liberty, or might it not unite with the nitrogen, and form a chloride of nitrogen? Suppose the cyanogen to be combined with hydrogen, the decomposition of the hydrocyanic acid would be effected first by the chlorine combining with the hydrogen, forming muriatic acid, and secondly with the carbon, forming chlorocarbonic acid. If hydrogen, in any other combination, should exist, would not the chlorine in every case decompose such compound, and thereby destroy its deletereous properties by taking away its hydrogen? I think it will be proved, some time or other, that the miasma, which produces yellow fever, is a compound of carbon and azote, with hydrogen, acting under particular circumstances and conditions.
Various other means, besides those we have stated, have been recommended to prevent the effect of contagious matter, such as odoriferous substances, preparations of camphor, aromatic vinegar, called the vinegar of four thieves, &c. but all come short of the effect, and may be regarded as nostrums. The vapour of burning sulphur, or sulphurous acid, is used in the East against the plague; but this is inferior to either of the other acids, of which chlorine, formerly called oxymuriatic acid, is to be preferred. A mixture of four parts of common salt, one of black oxide of manganese, and two of sulphuric acid, or muriatic acid poured on manganese or red lead, will generate chlorine gas. Morveau's disinfecting apparatus contains the above mixture. The free use of this gas in apartments, &c. &c. cannot be too strongly recommended.
[15] On this subject, see a paper by Mr. Howard in the English Philosophical Transactions, for 1802, and by Vauquelin in the Journal des Mines, No. 76.
[16] For the history of saltpetre, the reader may consult, with advantage, Beckman's History of Inventions.
[17] "The affinity of charcoal for oxygen is so considerable, that instances have been known of its undergoing spontaneous combustion by simple contact with the air. An occurrence of this kind took place at the powder mills of Essonne, in France. (An. de Chim. 36, p, 93.) A large quantity of recently burnt charcoal had been ground in the usual manner, and was deposited in a large receptacle for future use; some days after, the door of the magazine being opened, in order to remove a part of the charcoal, an extraordinary heat was perceived, and immediately a train of fire was observed, spreading over the surface of the charcoal, and which was not extinguished without much difficulty." Aikin's Chemical Dictionary, vol. i, p. 238.