_Certified._--The perpetual Secretary of the Academy of Medicine. Signed, Pariset. _Reflections._--The mixture of the acid sulphate of alumine and potash, of the nitrate of potash, and the chloride of sodium, furnished me, at first, with some favourable results. But when new experiments were attempted at a temperature above 10° of centigrade, this liquid, which I only employed as a bath, did not answer my expectations. I then tried to inject bodies with concentrated solution, which were afterwards consigned to a bath of the same nature. The preservation was thus rendered more durable; but still it did not balance the influence of an atmosphere very warm and very humid, prolonged for any length of time. I observed that after twenty-four hours of immersion of the bodies in the bath, all the alumine was absorbed: this fact, well established, was a gleam of light to me. Since the preservation is produced by the combination of geline with alumine, and as the alumine furnished by the acid sulphate does not inherit enough of the preservative element, let us have recourse to the salts of alum, richer in alumine, and more soluble in water. The following are the data on which I rely: _To find a salt of alum capable of effectually preserving bodies, and which, by the moderation of its price, may be extensively employed in amphitheatres._ I abandoned my trials with the nitrate of alumine, this being excluded by its _high price_. The chloride of alumine, with which I had experimented, is liable to equal objections: 1. Because, owing to its excessive affinity for water, it instantaneously dries the internal membrane of the artery, and obliterates the canal, rendering it impossible to finish the injection. 2. Besides, admitting the injection to have been completed by the introduction, in the first place, of a little oil of turpentine, the hydrochloric acid contained in the flesh injures the instruments, and impedes dissection. Further, the chloride of aluminium, like all the soluble chlorides, is a bad agent in dissections, being hygrometric. The acetate of alumine is an excellent preservative of animal matters, as will be seen by referring to the observation cited at the end of the last chapter; but it is costly, and on this account cannot be employed in amphitheatres. It was necessary, then, to search for a more economical method; this I have found in the _simple sulphate_ of alumine. This salt, but indifferently known, no one having thought of it before me, is of a simple preparation and moderate price. _A killogram of this salt, costing about twenty cents, dissolved in two quarts of water, is sufficient in winter to preserve a body fresh, by injection, for three months._