Manual of vital function testing methods and their interpretation / by wilfred M. Barton.

  • Barton, Wilfred M. (Wilfred Mason), 1871-1930.
Date:
[1917]
Catalogue details

Licence: In copyright

Credit: Manual of vital function testing methods and their interpretation / by wilfred M. Barton. Source: Wellcome Collection.

    95/326 (page 91)
    fice.^ The strength of silver solution used in the test o is such that 1 c.c. corresponds to .01 gm. of sodium chloride. Such a solution contains 29.06 gms. of pure fused silver nitrate to the liter. The technic of the estimation is as follows: 10 c.c. of urine previousl}^ freed from albumen are put in an Erlenmeyer flask or porcelain capsule and 100 c.c. of water added and several drops of potassium chromate solution, enough to produce a distinct yel¬ low color. The standard silver solution is added from a burette, stirring until the reddish orange color wliich appears first where the drop falls is distributed. The first permanent orange color trace is the end of the reac¬ tion. The operation should be repeated if necessary, to make certain of results. The number of c.c. used multiplied by .01 gives the amount of sodium chloride. The results are a little high but near enough for prac¬ tical purposes. A rough estimate of the amount of chloride in the urine may be made as follows; To a test tube of clear urine non-albuminous, add 10 drops of pure UNO;; and one drop of AgNO.^ (1 to 8). If chlorides are normal or increased, tlie precipitate is a compact ball whicli sinks to the bottom. If dimin¬ ished, the ball is less compact. If much diminished, only a cloud is produced without solid flakes. This last represents a chloride content of 1% or less. 3. Estimation of Urinary 'Nitrogen as an Index of Renal Function When functional tests of the liver were being dis¬ cussed (t>.s.) considerable emphasis was laid upon in- ’ The Lutke-Martius method is often recommended, see Salili’s Diagnostic Metliods, 1911, p. 455.