Directions for laboratory work in physiological chemistry : for the use of students in the University and Bellevue Hospital Medical College / Holmes C. Jackson.

  • Jackson, Holmes C. (Holmes Condict), 1875-
Date:
1902
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Licence: In copyright

Credit: Directions for laboratory work in physiological chemistry : for the use of students in the University and Bellevue Hospital Medical College / Holmes C. Jackson. Source: Wellcome Collection.

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    of c.c. of the alkali necessary to neutralize the acid and 20 corresponds to the amount of NH3 liberated from the 25 c.c. of urine. Sugar (Polarization). See demonstration. PATHOLOGICAL URINARY CONSTITUENTS. Albumin and Globulin. In testing urines suspected of containing proteid, the fluid should always be perfectly clear. This can be accomplished either by repeated filtration through paper or asbestos or by shaking with magnesia. The following tests are best suited for ordinary conditions: 1. Heat Test.—Warm 5 c.c. of clear urine to boiling and add 3 to 6 drops of dilute acetic acid. If the urine contains more than a small amount of albumin, this will settle out in flocks after the addition of acid. When mere traces are present the solution may only become turbid and should then be com- pared to the urine before heating, but to which the same amount of acid has been added. This test is only of value as a positive one. When a negative result is obtained other tests should be tried with a view to confirmation. In some cases the addition of acetic acid to boiled urine may give rise to a faint precipitate or turbidity which disap- pears upon shaking. This is caused by the formation of acid albumin, which may be salted out with ^ volume of saturated NaCl after the addition of more acetic acid to keep the phos- phate in solution. Faintly alkaline or amphoteric urine may