Outlines of the clinical chemistry of urine / by C.A. Mac Munn.

  • Macmunn, Charles A., 1852-1911.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of the clinical chemistry of urine / by C.A. Mac Munn. Source: Wellcome Collection.

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

    254/296 (page 232)
    The quantitative analysis of tlie constituftnts of urinary calculi may be carried out as follows :— (1) The luater is estimated by drying a weighed portion of the powdered calculus at 100° until its weight is constant. (2) For estimating uric acid, the powder is digested with dilute hydrochloric acid for twenty-four hours, the uric acid collected on a weighed filter; then proceed as described under uric acid (p. 67). (3) The phospJioric acid is estimated in half the hydro- chloric acid solution, after making it alkaline, and then acidulating with acetic ,acid, and titrating with uranium solution as described under phosphates (pp. 128—130). (4) Lime and magnesia are estimated in the other half of the hydrochloric acid solution, by removing the lime as oxalate in the acetic acid solution [see under B. (&)], and precipitating the filtrate with phosphate of sodium and ammonia (see p. 138). (5) Oxalic acid, if present, separates in combination as oxalate of lime. It is converted into caustic lime, and then weighed. If the amount of calcium is to be estimated in a calculus, the weight of the caustic lime so obtained must of course be added. (6) Ammonia may be estimated by Schlosing's or Sutton's method (p. 137). The qualitative composition of calculi may be roughly arrived at as follows :— If the powder ignited on platinum foil leaves a residue, as described under B above, to a part of the original powder the murexide reaction may be applied :— (1) A purple colour is developed, showing at once that iiric acid or urates are present; or (2) No purple is developed, then note whether the calculus melts under the blow-pipe flame. {a) If it does, then the calculus is composed of amnionio- magnesian phosphate, also probably of some calcium phosphate, and is the fusible calculus.