Physiology and pathology of the urine : with methods for its examination / by J. Dixon Mann.

  • Mann, J. Dixon (John Dixon), 1840-1912.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Physiology and pathology of the urine : with methods for its examination / by J. Dixon Mann. Source: Wellcome Collection.

    62/348 (page 42)
    which, when dissolved in boiling water, is partially reduced ; but it gives no coloration with ferric chloride. All these fatty acids have distinctive, penetrative odours; the odour of formic acid is peculiarly pungent, like that of sulphur dioxide. Their boiling-points differ: formic acid boils at ioo° C. ; acetic acid at 118° C. ; propionic acid at 1410 C.; butyric acid at 163° C. Except formic and acetic acids, all the fatty acids, on the addition of calcium chloride, are separated from their solutions in water and form an oily layer on its surface. LACTIC ACID. C3He03. Lactic acid or a-hydroxypropionic acid is miscible with water, alcohol, and ether, in all proportions. When heated with dilute sulphuric acid it is decomposed into aldehyde and formic acid. Lactic acid forms metallic and ethereal salts. Sarcolactic acid has the same constitution as lactic acid, but differs from it in being optically active; free sarcolactic acid is feebly dextro-rotatory ; its salts are feebly kevo-rotatory. Under ordinary conditions lactic acid is not present in urine. It appears in consequence of imperfect oxidation, such as is produced in animals by placing them in a closed chamber of limited air- capacity, and in man by carbon-monoxide poisoning, or by an epileptic seizure. Araki1 found, in cases of acute poisoning in which lactic acid was excreted, that loss of glycogen occurred, the imperfect oxidation of which furnished the lactic acid. In some severe diseases of the liver, notably in acute phosphorus poisoning, and in acute atrophy of the liver, lactic acid appears in the urine. Lactic acid has been found in the urine after prolonged muscular exercise, in eclampsia due to epilepsy, or occurring during gestation. Zweifel 2 regards the lactic acid as the exciting cause of the con- vulsions. On the other hand, Donath 3 and Doesschate 4 consider that the convulsions produce the lactic acid. In addition to the conditions already named, lactic acid has been found in cirrhosis and in acute atrophy of the liver, in blood diseases, such as pernicious anaemia and leukremia, in the vomiting of pregnancy (Underhill),5 in poisoning by morphine, cocain, arsenic, phosphorus and amyl nitrite, and also in various diseases immediately before death. Separation.—Lactic acid may be extracted from urine, after free acidulation with sulphuric or phosphoric acid, by large amounts of 1 Zeiluchr. f. physiol. Client., 1891. 2 Mil/nchcncr wed. J! ochenxchr., 1906. 3 Berliner Win. Wocheiutehr., 1907. 4 Zeitschr. j. physiol ('hem., 19°7> * Jtnirn. Biolog. C/tem., 1907.