5'j 



to the lo cc. mark with the urine to be tested, and 3)^ cc. 

 of potassium ferrocyanide (i to 10) are added ; i^ cc. 

 of acetic acid are next added and the reagents and 

 urine are thoroughly mingled by inverting the tube several 

 times. The tubes are placed in the centrifuge and revolved 

 until all of the albumin has settled, leaving the fluid above 

 perfectly clear. The bulk percentage of albumin is then 

 read off, each ^^ cc. representing i % bulk measure of 

 albumin. 



XXI. 



SUGAR IN THE URINE. (GLYCOSURIA.) 



272. It is maintained by many that the merest trace of 

 g^lucose or grape sugar is normally present in urine, and that 

 sugar in slightly larger quantities may appear transitorily 

 without pathological significance. In diabetes mellitus it 

 ■occurs in con.siderable amount. 



Characters of diabetic urine. The quantity of urine passed 

 is very large, even to 10,000 cc. in 24 hours; the specific 

 gravity is high, 1030 — 1045 ; the color is usually a very 

 pale straw, from the dilution — not diminution — of the uri- 

 nary pigments ; the urine is often .somewhat turbid ; it has 

 a heavy sweet smell, and usually froths when poured from 

 one vessel to another. 



The presence of albumin interferes with tests for sugar, 

 and the urine should first be tested for the presence of al- 

 bumin. 



273. Trommer's te,st. To about 3 cc. of urine in a test 

 tube add just enough copper sulphate solution to tint the 

 urine. Add about 3 cc. of 20% potassium hydrate, a green- 

 ish blue precipitate may at first be thrown down, but disap- 

 pears on shaking. Heat the mixture to the boiling point. 

 If sugar be present, the color changes to a yellowish or red- 



