CHAPTER VIII. 



DISEASES OF THE URINARY SYSTEM. 



THE URINE IN HEALTH AND IN DISEASE. 



As renal diseases are intimately connected with alterations 

 in the character of the urinary secretion, a knowledge of 

 the chemical composition of the urine, and of the alterations 

 it may undergo in disease, is of great importance. 



THE URINE IN HEALTH.— Healthy urine is an amber- 

 coloured fluid, varying in composition in difl"erent animals, 

 but containing in all analogous products of nitrogenous 

 waste and various salts. 



In the carnivorous animal it is a clear watery fluid of 

 acid reaction. In herbivorous animals it is either alkaline 

 when secreted, or very soon becomes so ; and is often cloudy, 

 depositing a sediment on standing. 



These diff"erences in the character of the urine depend 

 upon the nature of the food of the animal. 



If a herbivore be fed solely upon a nitrogenous diet, the 

 urine becomes acid, as also it does in certain diseases. In 

 inanition, also, where the body may be said to feed upon its 

 own tissues, the urine of herbivora likewise becomes acid. 

 Similarly, if a carnivorous animal be fed upon vegetables, 

 the urine becomes alkaline and cloudy. 



The urine of the mammalia contains a large amount of 

 water, and in the horse has a specific gravity of 1030 — 1050. 



