Notes for students in chemistry : being a syllabus of chemistry compiled mainly from the manuals of Fownes-Watts, Miller, Wurz, and Schorlemmer / by Albert James Bernays.

  • Bernays, Albert James, 1823-1892.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Notes for students in chemistry : being a syllabus of chemistry compiled mainly from the manuals of Fownes-Watts, Miller, Wurz, and Schorlemmer / by Albert James Bernays. Source: Wellcome Collection.

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    notice: Saliva. An opalescent, viscid liquid, ■which froths on agitation. The solids vary from 0.4 to 0.84. In addition to epithelial particles, and to the mucus derived from the mouth, the saliva contains ptyalin which resembles sodium albuminate. It constitutes one-third of the soluble solids of the suliva, and converts starch into dextrin and dextrose. Further, the saliva is faintly alkaline. Besides carbonates and lactates of potas- sium and sodium, it contains sulphocyanide of potassium, car- bonate and phosphate of calcium, the two last, together with salivary mucus, constituting the tartar of teeth. The gastric juice elfects the digestion of the albuminoid constituents of food. It is a clear colorless liquid, of peculiar odor; very acid after ingestion of food. Very powerful antiseptic. Does not become turbid when boiled. The acid consists of lactic and hydrochloric acids, with traces of butyric and propionic. Besides certain salts, it contains Pepsin, an albuminoid body, soluble in water, but insoluble in alcoliol or in ether. Wlieu boiled, pepsin loses its power of effecting digestion : its aqueous solution is precipitated by CUHg, but not by CygFeKj, in ai'etic acid solutions. Dried pepsin with 20 to 50 per cent, of starch, is an article of commerce. The Pancreatic fluid, some- what resembles saliva. It aids in the assimilation of fats. Sp. gr. J.008. Contains about 10 per cent, of solids, among Wllich LEUCIN C5H1n.H2N.COOH, XANTHIN CsH^NjO^, GUA^^N CjH5N50 and inosite CcHi206. Further it contains albumin, and becomes coagulated when heated. Mucus. A tough, viscid secretion, in which epithelial particles can be traced in dift'erent stages of disintegration. It swells up in, but is uot dis.solved by, water: mucin gives the glairy consistence to the mass, and is turned yellow by nitric acid, not precipitated by Cl„Hg, but coagulated by alcohol. The Urine. From arterial blood by the kidneys. Average sp. gr. 1.02. The quantity passed by an adidt varies from 40 to 50 oz. per day. Amber-colored, of slight acid reaction, and peculiar odor. It soon begins to putrefy, and becomes alkaline I'rom the conversion of uhea C0N.,H, + 20H._, into ammoxrm CARBONATE : the mucus of the bladder acting as a ferment. Besides water 95.680 per cent., and urea CONjH^, r.420 per cent., the urine contains mucus 0.016, uric acid CjH,N,03, 0.037 ptr cent., alcoholic extract i . 25 5, aqueoi s extract 0.250, sodium chloride 0.722, rHOSPHATES, sulphate.s, &c., 0.613 per cent. The urine of bcrbivora is rich in hipitric ACID CII.,.NH.C;H.,O.COOII. The colorimr matters of the urine. Unocnuo-ME and ui!Omelanin C3„Hj3N;0,|,. The uriufc is the chief oii(,let of the i^Ueto nitrogenized tissues. Lehmann secreted 821 grains of urea, and 21.6 grains of uric acid, per 24 hours, on au animal diet; on a vegetable diet 348 grains of