CONGESTION OF THE KIDNEYS— HYPEREMIA 387 



The chemical test for sugar in the urine is best made by 

 using Trommer's test, which is as follows: 



A few cubic centimeters of urine are put into a test-tube, 

 after removing any albumin which might be present, dilute 

 it' with an equal volume of water, render it alkaline with a 

 small quantity of sodium hydrate, then add drop by drop 

 a 4 per cent, solution of copper sulphate until the liquid is 

 clear and the sediment dissolved, then heat until it boils. If 

 sugar is present, a reddish-yellow vapor appears at the sur- 

 face of the fluid. The bismuth test is often used for the same 

 determination. The albumin is removed from 10 parts of 

 urine and added to this is 2 parts of subnitrate of bismuth, 

 4 parts Rochelle salts, and 100 parts of a 10 per cent, solution 

 of sodium hydroxid. This mixture is boiled for five minutes. 

 It becomes black if sugar is present. 



To determine the quantity of sugar present the saccharom- 

 eter is used. The urine is fermented by adding a small 

 quantity of yeast. Graduated glass tubes or other appa- 

 ratus are necessary to determine the exact quantity of sugar 

 present. 



Physically the urine varies in color and amount, depending 

 a great deal upon the kind and amount of food, the condition 

 of the kidneys, and the species of the animal. 



CONGESTION OF THE KIDNEYS. HYPEREMIA. 



This condition is divided into two forms, viz.: (a) Acute 

 hyperemia (arterial hyperemia), (b) passive hyperemia 

 (venous hyperemia) . 



Acute Hyperemia.— Etiology.— The causes of this condi- 

 tion are usually the same as those producing acute nephritis. 

 Irritating foodstuffs, chemicals and various diuretic com- 

 pounds, are the most common things producing acute hyper- 

 emia. It may occur during the course of infectious diseases 

 (distemper, rabies). Plethoric animals frequently have active 

 hyperemia of the kidneys. 



Pathology.— The kidneys are enlarged, swollen, softened 

 and highly reddened. The arteries and capillaries are found 



