246 INFECTIOUS AND PARASITIC DISEASES. 



between 1005 and loio; those containing sugar, between 

 1030 and 1040. To be sure, these hmits are often 

 exceeded or diminished. 



The reaction of normal urine is acid, 

 Reaction, although specimens passed at different 

 times may be neutral. The reaction of a 

 urine is obtained by wetting pieces of filter-paper which 

 have been colored red or blue by saturation with red or 

 blue litmus. If a urine be acid it will impart to the blue 

 paper a red color; if alkaline, the red paper will be 

 changed to blue. Normal urines sometimes alter the 

 color of both papers slightly; such urines are said to be 

 amphoteric. The latter is of no significance. 



Albumin in urine is always an indication of 



Albumin, disease. Tests for its presence should be 



made as a routine procedure. 



To determine the presence of albumin. 



Nitric (i) fill a test-tube two- thirds full of urine 



Acid Test, and apply gentle heat to the upper surface 



until it begins to boil. Now add a few 



drops of concentrated nitric or acetic acid. Should the 



urine remain clear it is free from albumin; if cloudy 



upon boiling, and the cloud does not clear up upon the 



addition of the acid, it contains albumin. 



(2) Add a few cubic centimeters of con- 



CoNTACT centrated nitric acid to a test-tube and. 



Test. while inclining the tube at an angle of 



about forty-five degrees, with a pipette let 



