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.

551/602 page 511

$heat test, with the addition of a small definite quantity of acetic acid, as the best test for the detection of small quantities of albumin.] 1. Quantitative Estimation of albumin. —100 c.c. of urine are boiled in a cay)sule, some acetic acid being lütiniately added, whereby the albumin is precipitated in flakes. The precipitate is collected on a weighed, dried (110°), ash-free filter, and repeatedly washed with hot water, then with alcohol, and dried in an air-bath at 110°. The weight of the filter is deducted, and finally the dried filter with the albumin is burned in a weighed platinum capsule, and the weight of the ash also deducted. [This method is not available for the busy pi'actitioner on account of the time it takes. Practically, it is sufficient to compare from day to day the proportion that the precipitated albumin bears to the bulk of the urine tested. A graduated tube may be used, so that after the precipitate has subsided, the physician may see what pro- portion of the Avhole the precipitate occupies,] Esbach's Albuminimeter (fig. .319).—A glass cylinder is filled with the urine up to the mark U, and to R with the precipitant (20 citric acid, 10 picric acid, 970 water). The vessel is corked and turned upside down several times to secure the mixture of the fiuitls. After twenty-four hours the coagulated albumin subsides, when the graduation on the tube indicates the number of grams of albumin per 1000 c.c. of urine. Very albuminous urine must be previously diluted. [Suppose the amount of deposit to reach to 3, and the patient passed 1800 c.c. of urine in 24 hours, the amount of albumin is 1 •8x3 = 5-4 grams in 24 hours. That is, 3 grams in 1000 c.c, there- r 1800 X 3 . . -, tore = 5 '4. ] 1000 \ 2. Serum-globulin occurs only in albuminous urine, and is frequently present. Its presence is ascertained by [neutralising and] adding powdered magnesium sulphate in excess to the urine ; when it is present it is precipitated (§ 32), The more globulin there is in the presence of albumin, the more difficult it is to pre- cipitate it. Sometimes, Avhen an albuminous urine is dropped into a large cylinder of water, each drop as it sinks is followed by a milky train, and when a sufficient number of drops have been added, the water becomes opalescent, the opalescence disappearing on adding an acid. The globulin is kept in solution by common salt and other neutral salts, but when these are largely diluted, the globulin is precipi- tated [Roberts). 3. Peptone occurs in some specimens of albuminous urine, but also in non- albuminous urine. Maixner found it constantly in the urine in all cases where suppuration is present, and even in phthisis, constituting pyogenic peptonuria. Peptone occurs in pus, and the peptonuria in these cases is a sign of the breaking up of the pus-cells [Hofmeister). Also when many leucocytes are broken up in the blood (haematogenic). It occurs in cases where there is great disintegration of albuminous tissues, e.g., in cancer, [suppurative diseases, empyema, croupous pneumonia, phosphorus-poisoning, &c.]. It is frequently found after child-birth. Ammonium sulphate precipitates all proteids except peptones (p. 464). [The only satisfactory test for peptone is to precipitate all the other proteids with ammonium sulphate, and any proteid remaining in solution in the filtrate must then ha peptone. Many of the so-called cases of peptonuria [Martin) (in sup- purative diseases) are really due to the presence of deutero-proteose. This last substance gives all the reactions for peptone except the following two. It is precipitated by ammonium sulphate, while peptone is not. It gives no precipitate with nitric acid unless a considerable amount of salt is added, and this precipitate disappears on heating and reappears on cooling, while peptone gives no precipitate with nitric acid.] [When peptone is injected into the blood it is excreted in the urine as peptone (p, 36). Deutero-albumose similarly injected appears as peptone,] Test.—Separate the albumin by boiling and the addition of acetic acid. Treat the filtrate Avith three volumes of alcohol ; this precipitates the peptone, which, Avhen dissolved in Avater, gives the characteristic reactions for peptone (§ 166, 1.). 4. Proteoses, i.e., Hemialbumose or propeptone occur very rarely, e.g., in osteomalacia and intestinal tuberculosis [Bmce Jones). The urine is heated to saturation with NaCl and a large quantity of acetic acid added,and filtered Avhile hot, to separate the albumin and globulin. In the cold filtrate hemialbumose forms a turbidity, which is redissolved by heat. The precipitate thrown doAvn by HCl and HNO3 is soluble by heat [Kühne). The precipitate is isolated by filtration, and dissolved in a little warm Avater, wdien it gives with HNO^ a yelloAV reaction ; like peptone the solution gives the biuret-reaction (p. 466). [Another proteose occurring in the urine is deutero-proteose, Avhich has been mistaken for peptone (see above).] 5. Egg-albumin appears in the urine when much egg-albumin is taken in the food, and also Avhen It is injected into the blood-vessels (§ 192, 4). According to Semmola, the albumin present in the urine in Bright's disease has undergone a molecular change (similar to egg- albumin), and hence it is excreted. Fig. 319. Esbach's albumini- meter.$