Outlines of physiology in its relations to man / by John Gray McKendrick.

  • John Gray McKendrick
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of physiology in its relations to man / by John Gray McKendrick. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    weak acids, but it is dissolved by alkalies and concentrated acids. Elastine is dissolved only in concentrated alkalies. The composition of protagon has been represented by the following formula:— When boiled with baryta water, it decomposes into phospho- glyceric acid (CsHgPOe), stearic acid {Q-i^-^qO^, and a very alkaline substance named neurine (CgH^g]Sr02). From all secretions of mucous membranes a substance may be readily precipitated, in a J&occulent form, by alcohol or acetic acid, which is termed muci7ie. It is difficult to obtain it in a state of absolute purity, and therefore the formula given by Hoppe-Seyler may be regarded as approximative : 3. Nitrogen Bases and their Allies. When we examine the chemical constitution of plants, we find they contain lion-nitrogenous and nitrogenous bodies. As examples of the first, we have (1) carbohydrates, such as cellulose, starch, dextrine, gum, and cane and grape sugar; (2) the varieties of the essential oils and resins; and (3) vegetable acids. The nitrogenous compounds comprise the colouring matters of plants, the principal of which is chlorophyll, and organic bases termed alkaloids. These bases contain nitrogen, in addition to carbon, oxygen, and hydrogen. The following are examples :— Morphine, . . Ci7Hi9]S'03. I Strychnine, . . CgiHgglSr.^O^. Conine, . . CgH^gN. ] Nicotine, . . 0101114X2. Chemically, these bodies are regarded as compound am- monias—that is, bodies in which one, two, or three equi- valents of hydrogen are replaced by radicles. Thus conine may be represented as ammonia in which two atoms of