THE MICROSCOPE IN DIAGNOSIS. 303 



BILE. 



Bile in urine, if present in large quantity, can be recog- 

 nized by the eye. In testing for albumen by nitric acid, 

 the greenish color produced by bile will also attract notice. 

 A more delicate test consists in placing a drop or two of 

 urine and a drop or two of strong nitric acid near together 

 on a white plate and allowing one to run into the other. 

 As the acid mixes with the fluid, a play of colors, com- 

 mencing in green and terminating in red, passing through 

 various shades, will be observed. 



Bile in urine indicates jaundice, and may aid in the 

 differential diagnosis of discolorations of the skin and 

 conjunctiva due to other causes. It may show an incipi- 

 ent jaundice before the tissues are generally affected, and 

 its disappearance may afford evidence that the attack is 

 passing off* when the effects of jaundice may be visible 

 elsewhere. 



ALBUMEN. 



In suspected albuminuria, samples should be examined 

 which were passed at different times of the day, as before 

 eating in the morning, and after eating in the evening. 

 Care should be taken to have clean bottles, test-tubes, etc. 

 The urine should be subjected to a double test, by boiling 

 in a test-tube and the subsequent addition of a drop or 

 two of nitric acid, and by the addition of strong nitric 

 acid to a separate portion of the cold urine. In the latter 

 test a cloudy ring of albumen appears at the junction of 

 the two fluids. 



The quantity of albumen may be estimated sufficiently 

 for clinical practice by allowing the precipitate formed on 

 boiling to subside for a definite time, twelve to twenty- 

 four hours, and observing how much of the tube is occu- 

 pied, as a half, a fourth, an eighth, etc. 



