Volume 1

A text-book of physiology / by Henry P. Bowditch [and others] ; edited by William H. Howell.

Date:
1900
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: A text-book of physiology / by Henry P. Bowditch [and others] ; edited by William H. Howell. 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.

    512/608 (page 508)
    (2) By the action of strong sulphuric acid on common salt, 2NaCl + H2SO4 Na^SO^ + 2HC1. (3) By the action of primary acid phosphate of sodium on common salt, NaCl + NaH^PO, = Na^HPO, + HCl. This, according to Maly, represents the process in the cells of the gastric glands. Properties.—Hydrochloric acid readily unites with most metals, forming chlorides. It causes a gelatinization of the proteids and seems to unite with them chemically. Such gelatinization is a necessary forerunner of peptic di- gestion. The cleavage products of peptic digestion (peptones, proteoses, etc.) combine with more hydrocliloric acid than the original more complex proteid.' Free hydrochloric acid of the strength of the gastric juice (0.2 per cent.) inverts cane-sugar at the temperature of the body,^ and inhibits the action of bacteria. Hydi'ochloric acid is derived from decomposition of chlorides in the secreting cells of the stomach. It has been shown that the excretion of common salt in the ui'ine is decreased during those hours that the stomach is active, while the acidity of the urine decreases. If, in a dog with a gastric fistula, the mucous membrane of the stomach be stimulated and the gastric juice be removed as soon as formed, the urine becomes strongly alkaline with sodium carbonate (the excess of Na liberated taking this form) while the chlo- rides may entirely disappear from the urine.^ Respiration in an atmosphere containing 0.5 per cent. HCl gas becomes very uncomfortable after twelve minutes.'' If the bases (K, Na, Ca, Mg, Fe) of gastric juice and then the acid radicals (CI and P2O3) be determined, and the phosphoric anhydride be united with the proper bases, and then chlorine with the rest of the bases, there still remains an excess of chlorine which can only have Ijelonged to the hydrochloric acid present. To detect free hydrochloric acid put three or four drops of a saturated alcoholic solution of tropaeolin 00 in a small white porcelain cover, add to this an equal quantity of gastric juice, evaporate slowly, and the presence of hydrochloric acid is shown by a beautiful violet color, not given by any organic acid.^ Gtinzburg's reagent consisting of phloroglucin and vanillin in alcoholic solution, warmed (as above) with gastric juice containing free hydrochloric acid, gives a carmine-red mirror on the porcelain, not given by an organic acid.* Chlorine in the body is ingested as chloride, and leaves the body as such, principally in the urine, likewise through the sweat and tears, and in traces in the feces. Bromine, Br = 80. Salts of bromine are found in marine plants and animals, but their physiological im- portance has not been established. Bromine is a fluid of intensely disagreeable odor, ^ Chittenden : Cartwright Lectures on Digestive Proteolysis, 1895, p. 52. ^ Ferris and Lusk: American Journal of Physiology, 1898, vol. i. p. 277. ' E, O. Schouniow-Simanowski: Archiv fiir exper. Pathologie und Pharmakologie, 1894, Bd. 33, S. 336. * Lehniann : Archiv fiir Hygiene, Bd. 5, S. ]. ^ Boas : Deutsche medicinische Wochenschrift, 1887, No. 39. * Giinzburg : Centralblatt fiir klinische Medicin, 1887, No. 40.