The aluminous salts are those alone which I find possessed of the property of preserving animal matters; their bases combine with geline to form a particular compound, the acid being set free. The vegetable kingdom furnishes but few products capable of preventing or retarding putrefaction; alcohol is nearly the only substance possessing the property. It preserves in the same manner as the salts, by imbibing a portion of the water of composition; it bleaches, discolours, and hardens the organs. Alcohol is the only substance employed up to the present for preservation; but its action upon the tissues, its extreme volatility, the difficulty of transporting it, and its extreme dearness, makes another process desirable. Tannin cannot be employed, because water does not contain enough of it in solution to render an injection of it preservative; a corpse immerged, even in a great mass of tannin, is no better preserved, the skin is tanned, but the flesh decomposes.[O] [O] Entire bodies of both men and horses have been found not unfrequently, preserved for centuries in the English bogs--which preservation has always been referred to the tannin in its fluid portion. These instances probably occurred at a low temperature. I have tried the experiment by immersing small quadrupeds in a saturated solution of powdered nut-galls, during warm weather, but always found it insufficient for preservation from putrefaction.--_Tr._ Gallic acid acts in the same manner, but yet more feebly than tannin. An oily, volatile, and very odorous substance, recently discovered, and to which the name _Creosote_, has been given, has been presented as a universal panacea, which, among other properties, ought to possess that of well preserving bodies. In order to assure myself of the truth of this assertion, on the 18th October, 1835, I injected a subject with one hundred scruples of creosote, dissolved in seven quarts water. On the 23d, the abdomen was very much swollen, and of a very strongly pronounced blue-green colour; on the 26th, the left side of the face, the right arm, and all of the left leg, were green; on the 30th of October, putrefaction was so much developed that it became necessary to bury the body. It may be objected, that the subject should have been at the same time steeped in a bath saturated with this substance; but its high price discouraged me from making such an experiment; besides I think that the odour of the creosote will always prove an obstacle to its employment. Alum, the acid sulphate of alumine, and of potash, have given me the first good results; but, slightly soluble when cold, they will not suffice when the atmospherical temperature rises above fifteen degrees, (cent.) A mixture of alum, of chloride of sodium, (common salt,) and of nitrate of potash, has succeeded better with me. I have tried the action of sulphate of soda, of chloride of calcium, (muriate of lime,) of hydrochlorate of ammonia, &c.; they were almost useless.