EXCESS OR DEFICIENCY OF THE INORGANIC CONSTITUENTS. 7l7 



Alterations as respects the matter of these compounds, 

 although not ascertainable by the observation of physical 

 characters, or the employment of physical tests, are yet 

 capable of being determined by appropriate chemical processes. 

 Density, as indicated by the urinometer, a most unsatisfactory 

 datum upon which to found any conclusion respecting the 

 character of urine, or the changes which it indicates, tells us 

 nothing. The acidity, usually feeble, may be determined to a 

 certain ^tent, both as to existence and character of stability 

 or otherwise, by litmus-paper and its after-treatment by heat ; 

 however, even from its slate of perfect solubility, hippuric acid 

 may be separated and demonstrated. 



/! Excess or Deficiency of the Inorganic Constituents. — 

 Although in the examination of urine as an index of disease 

 much more attention has been given to the consideration of 

 the condition and relative proportions of the constituent 

 organic matters referred to, it seems quite certain that with a 

 greater amount of attention we will find the amount, relative 

 proportion, and combinations of the inorganic constituents not 

 less important and deserving of attention. 



Of the entire amount of the inorganic materials of the 

 horse's urine, the greater part consists of salts of the akalies 

 and alkaline earths, chief of which are carbonates, with a 

 small amount of chlorides and sulphates. 



Considerable variations in the amount of these inorganic 

 compounds as a whole, as also in their relative proportions, are 

 of regular occurrence ; this variation depending as much pro- 

 bably on excessive or impeded metamorphosis and disturbance 

 of the normal interchanges occurring in the animal body, as 

 on the amount and character of the food received. 



In some constitutional diseases developed in connection 

 with particular localities and under certain dietetic conditions, 

 there seems, from what little we presently know, a distinct 

 change both in amount and relative proportion of several of 

 these inorganic salts. Also in several acute sporadic diseases 

 of an inflammatory tjrpe the varying quantities of several of 

 these discoverable in the urine, during particular stages of the 

 disease, is extremely interesting and highly suggestive. During 

 disease some of the constituents continue to be thrown off in 

 increased amount ; others probably are retained during the 



