To two drachms of fresh ox gall, were added two scruples of Magnesia, and two ounces of water, in one phial. Two scruples of calcined Magnesia with the same quantity of gall and water were placed in another; and a third containing two drachms of bile without any other addition than water, served as a standard, which began to have a rank smell in forty-eight hours, and in sixty hours was highly offensive. The calcined Magnesia and bile emitted a sweetish smell, something resembling that of the urine in a diabetes: the liquor which swam above was quite pellucid and colourless, whereas that of the other Magnesia was turbid and tinged green with the bile. Both were perfectly free from any putrid foetor; the latter continued so for ten days, and the bile with the calcined Magnesia remained unchanged as long as any notice was taken of it. EXPERIMENT V. Twenty grains of Magnesia preserved six drachms of ox's gall free from any signs of corruption for twenty-four hours after the standard containing gall and water, of each six drachms, had become putrid. A scruple of the calcined Magnesia mixed with the same proportions of gall and water, remained without any alteration as long as they were attended to, which was about ten days. EXPERIMENT VI. The putrid liquor which had been used as a standard in the fourth experiment, was divided into four parts, one of which was continued as a standard, to another was added about half a drachm of Magnesia, and an effervescence was procured by some drops of oil of vitriol. The offensive smell continued for a few minutes, but was soon much abated, and at length entirely sweetened. To another portion was added twenty grains of Magnesia only, this in fifteen minutes had almost lost its putrid smell, and in two or three hours became quite sweet. To the fourth was added the same weight of calcined Magnesia, which almost instantly deprived the liquor of every degree of putridity. The standard was then mixed with a scruple of crab's eyes, which, for about a minute, seemed to diminish the foetor, but it then returned as strongly as ever; whereas the others continued sweet for several days. EXPERIMENT VII. Two drachms of putrid bile, which had been kept closely corked in a phial since the year 1770, and smelled very offensively, were mixed in a cup with twenty grains of Magnesia, and half an ounce of water, and thereby restored to sweetness. Twenty grains of calcined Magnesia were also added to two drachms of the same bile: on stirring them a pungent smell was observed, like that of volatile salts, and half an ounce of water being put to the mixture, the bile was totally deprived of any putrid smell. Even five grains of the same powder sweetened two drachms of putrid gall. EXPERIMENT VIII.