160 DISEASES OF THE URINARY AND SEXUAL APPARATUS. 



the prostate (see Fig. 49). There are a number of abnormal sub- 

 stances found in the urine. The principal ones are albumin, 

 sugar, and the coloring substances of the bile. 



Urine of cystitis in the dog, containing cystic epithelium, hlood-corpuscles, 

 triple phosphate crystals, and bacteria. 



Albumin. The presence of albumin in the urine is always an 

 indication of disease. The best method to indicate its presence is 

 by Koch's test. The urine is boiled in a test-tube, having been 

 previously rendered acid in reaction by a small quantity of acetic 

 acid. It may become opaque from two causes :- from the presence 

 of albumin or from phosphates. We pour a small quantity of 

 nitromuriatic acid down the side of the tube, and if there is any 

 albumin present there will be a pronounced opaque line where the 

 acid meets the urine. 



Albumin occurs in the urine from two causes : first, in false or 

 accidental albuminuria, and true or renal albuminuria. 



The first occurs when there is free albumin in the urine from 

 accidental causes, where the albumin is added to the urine in its 

 passage from hemorrhage, inflammatory conditions in the passages, 

 or from purulent inflammations. In such cases the microscope 

 will easily make the differential diagnosis. 



True albuminuria is of much greater importance, as this condi- 

 tion is always a symptom of pathological alterations in the epithe- 

 lium covering the walls of the gland. Healthy epithelium will 

 always retain the albumin in the blood. 



We see true albuminuria in all forms of acute and chronic 

 inflammation of the kidneys, in fatty degeneration of the kidneys, 

 in amyloid kidneys, and in any altered condition of the circula- 

 tion, such as stagnating hypersem^as as a consequence of heart- 

 disease, chronic inflammatory conditions of the lungs, pleuritis. 



