An introduction to medical literature, including a system of practical nosology : intended as a guide to students, and an assistant to practitioners. Together with detached essays, on the study of physic, on classification, on chemical affinities, on animal chemistry, on the blood, on the medical effects of climates, on the circulation, and on palpitation / by Thomas Young.

Date:: 1823

Credit: An introduction to medical literature, including a system of practical nosology : intended as a guide to students, and an assistant to practitioners. Together with detached essays, on the study of physic, on classification, on chemical affinities, on animal chemistry, on the blood, on the medical effects of climates, on the circulation, and on palpitation / by Thomas Young. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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with the blood, for instance, bile ; others are more diluted ; but none are more concentrated. The secretions, or the fluids destined to be employed within the body for particular purposes, without being excreted, are alkaline ; but the ex- cretions, which are destined for evacuation, are all acid; for instance, sweat, urine, and milk; and the uncombined acid is the lactic. [The acid fluids contain a larger portion of alkaline phosphate than the alkaline fluids, probably be- cause the phosphoric acid is a product of spontaneous decom- position. Afh. III. 15. Djurk. II. 178-9.] 6. Cellular membrane. Of the cellular membrane we only know, that it is in great measure dissolved by slow boil- ing, and affords gelatin; a property which it possesses in common with cartilage and skin, although, from the dif- ferent facility with which these substances are dissolved, there is reason to think that their chemical constitution may also be different. This gelatin is not found as such in these substances, but i-s properly a product of the operation of boiling. The incorrect opinion, that gelatin is found already existing in the living body, and dissolved in its fluids, has been in great measure derived from the supposed separation of this substance by precipitation with infusion of galls. But while many other animal substances are precipitated by galls, the precipitate of gelatin has the distinguishing cha- racter of uniting in a thick mass like caoutchouc, which, when dry, becomes hard and brittle. Such a precipitate canuot be obtained from any animal fluid, except from urine, which has been long boiled with alkali, since the substances dissolved in urine are probably made to approach nearer to the nature of gelatin, by the effect of the alkali and of the boiling. The cellular membrane contains in its cavities a fluid, which has not been investigated, but which may probably be considered as identical with that which is found in the greater cavities of the body, in blisters, and in dropsy. It

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