Volume 1

Animal chemistry : with reference to the physiology and pathology of man / by Franz Simon ; translated and edited by George E. Day.

  • Johann Franz Simon
Date:
1845-1846
Catalogue details

Licence: Public Domain Mark

Credit: Animal chemistry : with reference to the physiology and pathology of man / by Franz Simon ; translated and edited by George E. Day. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    119/430 (page 95)
    recrj'^stallization, and dissolved in water, eannot be preeipitated by acetate of lead, nitrate of silver, or nitrate of the black oxide of mercury. If the fluid, dining evaporation, gives off an urinous odour some bydrocbloric acid must be added, and it must be allowed to stand for some time. If acicular crystals are formed, which, after being purified by recrystallization, and dissolved in water containing enough alkah to neutralize the acid of the crystals, give a white precipitate with the above-named tests, an orange with the perchloride of iron, and when moistened with nitric acid, and warmed, do not assume a purple-red colom', they consist of hippuric acid. If however the crystals are very minute, are not readily dissolved in water, and give, when moistened with nitric acid and wanned, a purple-red stain, they are uric acid crystals. 4. If the fluid which we are examining is of a brownish yellow colour, and if on treating a httle of it with an excess of nitric acid, the colom* successively changes to green, blue and red, then biliphsein is present. 5. On evaporating a portion of the fluid to dryness, pulver- ising it, and boiling it with ether, we obtain, by the evaporation of the ethereal solution, a fatty residue. If it be fluid, it is composed of olein, if it have a tendency to be solid, either stearin or margarin, or both are also present. The fatty acids, and probably free lactic acid, with traces of other sub- stances may be present, especially if the ether contaiued any alcohol or water. These substances remain in solution, on washing the fatty residue with water. The lactic acid may be easily recognized by its acid reaction; and the fatty acids may be detected by the addition of acetate of lead or acetate of copper to their alcoholic solutions. They are completely pre- cipitated in this manner, and a residue of pure fat is left, which must be again washed and the water removed by evaporation. The fat must then be saponified; if a portion of it resists this process, cholesterin or serolin, or both, must constitute a por- tion of the fatty residue. They must be taken up by ether, after the saponified portion has been evaporated to di*yness. Serolin is less soluble in alcohol, and melts at a lower tem- perature than cholesterin,* by which means the two fats may ‘ [Serolin melts at 95°, cholesterin at about 275°.]