154 LABORATORY METHODS OF 



contact of the urine and the acid (green, blue, violet, 

 red and yellow). This is Gmelin's Test for Bile. 

 Tyson. 



BLOOD. 



This is a common occurrence. The presence of the 

 same is detected by the color and the use of the mi- 

 croscope. The cause of the blood in the urine is a 

 common question asked the physician. It is caused 

 as follows: i. Local or renal congestion. 2. Trau- 

 matism of the ureters, bladder, calculi, acute cystitis, 

 and urethritis, simple and specific. 3. General dis- 

 eases, such as malarial-fever. The color of the urine 

 is the chief index to the beginning of the analysis. 

 The microscope comes in next. It is the surest method 

 to find the corpuscles in the urine before you say you 

 are dealing with a case of Haematuria. Since there 

 are so many other elements that resemble blood in color 

 it is not safe to go by the color alone. There are 

 many tests for blood, chemically, but these are not ab- 

 solute, so we will not spend the time on them. (See 

 Practice.) 



PYURIA. 



The presence of pus in the urine is called pyuria. 

 There are two tests for pus in the urine. 1st. Any 



