Annual report for the year 1903 (6th year of issue) / Metropolitan Asylums Board.
- Metropolitan Asylums Board (London, England)
- Date:
- 1904
Licence: In copyright
Credit: Annual report for the year 1903 (6th year of issue) / Metropolitan Asylums Board. Source: Wellcome Collection.
389/420 page 313
![specially mentioned, the food was milk, or bread and milk, which is practically pnrin-free. In 1895, Deniges5 described a rapid method of estimating purin bodies in urine which has been here adopted with some modifications. If a strongly ammoniacal silver nitrate solution of known strength, containing magnesium and ammonium chlorides, be added to a known quantity of urine, a three-fold pre¬ cipitate falls containing triple phosphate, silver biurate in combination with the magnesium salt, and silver compounds of the purin bases.6 In Deniges process, the silver in this purin precipitate, and from it the total purin is estimated with the aid of potassium cyanide from the amount remaining uncombined in the filtrate. To obtain the relative proportion of acid and basic purin a separate estimation of uric acid is necessary. It is first precipitated as ammonium biurate by saturation of the urine for two hours with ammonium chloride, and after filtration washing, and re-solution, is estimated in the way just mentioned. Twenty cubic centimetres of urine were usually taken for analysis, sometimes of necessity, at others because this small quantity allowed the estimation to be more readily repeated as often as required. The albumen was not removed. Deniges states that it does not interfere with his process, and its presence was not found to increase the experimental error of the modified method described. Further details of the original method are to be found in books and papers 7; it is here only necessary to examine the reliability of the present results. The three following examples show the divergencies to be expected when comparative estimations are made :— Nephritic urine, containing small quantities of blood and albumen, removed before analysis. Uric acid, estimated by Salkowski’s method. Total purins, Camerer's method : Xanthin bases by difference. The numbers represent grammes in 100 c.c. urine. Specimens a, 5, c taken on three consecutive days. a b c Uric Acid— Salkowski method ... ... ... Present process ... 0295 0297 •0450 •0123 •0138 •0378 •0201 •0195 •0378 Xanthin Bases — Camerer’s method •0055 •0209 [•0013]* Present process ... •0023 •008 trace. Total Purins— Salkowski-Camerer •035 •034 •021 Present process ... •047 •046 •038 * The value in brackets was obtained by use of Walker Hall’s nitrogen factor with the centrifugalised purin precipitate. Twenty-four hours are required for an estimation by Hall’s “ Purinometer.”—I. W. Hall, “ Purin Bodies,” p. 151. 5 G. Deniges, “ Jahresberieht fiir Thierchemie,” 1895, p. 84. ^Abstract.] 6 Neubauer and Vogel “ Analyse des Harns.” passim. 7 Neubauer apd Vogel, “ Analyse des Harns,”](https://iiif.wellcomecollection.org/image/b30300307_0389.jp2/full/800%2C/0/default.jpg)
