19 



tity of urine is increased the solids are increased in diabetes 

 mellitus; phosphaturia ; azotiiria (excessive secretion of urea). 

 Calculate the solids of the urines by the formulae 

 previously given. After obtaining the result for 1000 cc. 

 estimate the quantity in 1250 cc. of human, and 5450 cc. 

 of horse urine. In recording the tests use parallel col- 

 umns, one column for the horse and the other for the hu- 

 man urine. 



III. 



Qualitative Tests. In all cases the urines must be filtered 

 and perfectly clear before attempting the examination. 



INORGANIC CONSTITUENTS. 



These consist chiefly of sodium, potassium, ammonium,, 

 calcium, and magnesium, combined with hydrochloric, phos- 

 phoric and sulphuric acids. 



Water. The water of the urine is derived from the food 

 and drink, a small quantity being formed in the body. It var- 

 ies according to the activity of the sweat glands of the skin. 



Chlorides. Next to the urea the chlorides form the chief 

 portion of the urinary solids. The chlorides are increased 

 physiologically after the ingestion of salt foods and much 

 water ; mental and physical activities ; and during pregnancy. 

 Pathologically, they may increase after the crises of fevers ; 

 after the absorption of exudates; in diabetes (occasionally). 



The chlorides are decreased pathologically, in all acute 

 fevers; pneumonia (often entirely absent during the height 

 of the disease) ; in cholera; and in most chronic diseases. An 

 increase, or the re-establishment of the excretion of chlorides 

 in disease is generally a favorable sign. In pneumonia it is 

 a precursor of the crisis, and may often take place before other 

 symptoms reveal the favorable change. 



Test a portion of each urine with a few drops of 

 silver nitrate solution. A white, cheesy or curdy pre- 

 cipitate insoluble in nitric acid indicates the presence 



