Volume 1

A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling.

Landois, L. (Leonard), 1837-1902. Lehrbuch der Physiologie des Menschen. English

Date:: 1891

Credit: A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling. Source: Wellcome Collection.

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$oxygen (Pasteur). According to Brücke, it is the lactic acid, formed from the minute traces of sugar present in urine, which causes the acidity. According to Eöhmann, who recognises the acid fermentation as an exceptional phenomenon, the acids are formed from the decomposition of sugar, and from alcohol which may he present accidentally. While the urine is still acid, it becomes turbid and contains nitrous acid, whose source is entirely unknown. Ac- cording to V. Voit and Hofmann, phosphoric acid and a basic salt are formed from acid sodium phosphate, whereby part of the uric acid is displaced from sodium urate, thus causing the formation of an acid urate. Alkaline Fermentation. — When urine is exposed for a still longer time, more especially in a Avarm place, it becomes neutral and ultimately ammoniacal, i.e., it undergoes the alkaline fermen- tation (hg. 317). Fig. 316. Deposit in acid feniientatioii of urine. b, amorphous sodium urate ; c, uric acid oxalate. rt, fungus ; d, calcium 4. This condition is accompanied by the formation of the micrococcus nreae (fig. 317), (Pasteur, Cohn) and Bacterium ureee (figs. 317, 318), which causes the urea to take up water, and decompose into COg and ammonia. [CON^H, + 2H2O = (NHJ.COg]. Urea Ammonium carbonate The property of decomposing urea belongs to many kinds of bacteria, including even_ the sarcina of the lungs—whose germs seem to be univei'sally dißused in the air. These organisms produce a soluble ferment {Musculus) soluble which, however, only passes from the body of the cells into the fluid after the cell or organism has been killed by alcohol {Lea). The presence of ammonia causes the urine to become turbid, and those substances which are insoluble in an alkaline urine are precipitated— earthy phosphates, consisting of the amorphous calcic phosphate, acid ammonium urate (fig. 316, a), in tlie form of small dark granules covered with spines; and, lastly, the large clear knife-rest or coffin-lid form of ammonio-magnesic phos- phate, or triple phosphate (fig. 339). [The last substance does not exist as such in normal urine, but it is formed when ammonia is set free by the decomposition of urea, the ammonia uniting with the magnesium phosphate. Its presence therefore always indicates ammoniacal fermentation of the urine.] In cases of catarrh or inflammation of the bladder, this decomposi- mm Fig. 317. Deposit in ammoniacal urine (alkaline fermenta tion). a, acid ammonium urate ; h, ammonio magnesium phosphate ; c, bacterium ureee.$