CHEMICAL URINALYSIS. 175 



upper end of the cylinder. The readings on the ureometer will in- 

 dicate the number of milligrams of urea in 1 c.c. ; from this deter- 

 mination may be calculated the total amount eliminated in twenty- 

 four hours. 



Hypobromite may be prepared as follows : To 250 c.c. of water 

 add 100 grams of sodium hydrate. When ready to make the test, 

 add to 10 c.c of the sodium hydrate 1 c.c. of bromine, and then a 

 quantity of water equal to this mixture. 



2. Uric acid. Uric acid is a nitrogenous compound supposed to 

 be formed in the liver by the union of ammonia and lactic acid. 

 The quantity eliminated in twenty-four hours by the healthy adult 

 is about 0.5 gram. An excess occurs in leukaemia, fevers, lung and 

 heart diseases, tumors, etc.; an absence of uric acid occurs in 

 Bright's disease, gout, and other affections. 



A qualitative test may be made by strongly acidulating with hy- 

 drochloric acid a beakerful of urine. After standing twenty-four 

 hours, uric acid crystals will be deposited, which may be examined 

 with the microscope. 



3. Glucose. Sugar occurs temporarily in the urine with such 

 diseases as cholera, gout, intermittent fever, etc. Its presence be- 

 comes persistent in diabetes. It may be detected by Fehling's solu- 

 tion, Haynes' test, fermentation test, etc. 



Fehling's solution is prepared by dissolving 6.9 grams of copper 

 sulphate in 100 c.c. of distilled water. Then a second solution is 

 prepared by dissolving 34 grams of potassium sodium tartrate and 

 25 grams of potassium hydrate in 100 c.c. of water. In making the 

 test, place about 5 c.c. of each of these solutions in separate test 

 tubes, heat to boiling, and, after adding one to the other, add a few 

 drops of the suspected urine. If a yellowish-red precipitate is 

 formed, it indicates the presence of sugar. 



Hay lies' solution is prepared by mixing 30 grains of copper sul- 

 phate with one-half ounce of distilled water, then adding one-half 

 ounce of pure glycerine, and, after mixing, adding five ounces of 

 liquor potassse The test is made by boiling five to ten cubic centi- 

 meters of this solution in a test tube, and adding six to eight drops 



