37 



transitorily without pathologic significauee. The presence of 

 small quantities of sugar in the urine is designated as glycosuria ; 

 in larger quantities it is known as diabetes mellitus. The former 

 condition if habitual, is unnatural, and may terminate in the 

 latter. 



These diseased conditions do not necessarily point to dis- 

 eases of the kidney or urinary organs, but rather to the liver. 

 The kidney, in ridding itself of this product (dextrose), becomes 

 irritated, and this irritation extends down the entire canal, and 

 we thus have a real polyuria produced. 



Sugar, in sufficient quantity to react to ordinary tests, is 

 found in the urine physiologically during pregnancy and lac- 

 tation ; in infants under two months old ; in old persons living 

 largely upon starchy and saccharine food. Pathologically in 

 diabetes mellitus; in impeded respiration from pulmonary dis- 

 eases; in impeded hepatic circulation (functional and organic 

 diseases of the liver) ; in diseases of the central nervous system 

 (general paresis, epilepsy, dementia, puncture of the fourth ven- 

 tricle) ; in intermittent and typhoid fevers, by the action of cer- 

 tain poisons, as carbon monoxide, arsenic, chloroform and curare : 

 in abnormally stout persons. 



The persistent excretion of easily recognizable quantities of 

 sugar constitutes diabetes. The quantity of urine is often enor- 

 mously increased, as much as 10000 cc. being passed in 24. hours, 

 by man. The specific gravity is high, varying from 1025 to 1050. 

 The color is usually pale, from the dilution — not diminution — of 

 the urinary pigments. 



The presence of albumin, interferes with the tests for sugar 

 and must, in all cases, be removed by the addition of acetic acid 

 and heat. The urine, after being filtered, may then be used for 

 the sugar tests. 



The particular property of glucose, which is utilized for 

 its detection, is its action as a reducing agent — its disposition to 

 absorb oxygen. In this property it difPers strikingly from sac- 

 charose or common cane sugar. 



Principle of the Copper Tests. If a little copper sulphate 

 and an excess of a solution of caustic potash be added to a solu- 

 tion of glucose, a clear blue solution results. Without the glucose, 

 the alkali would precipitate the pale blue cupric hydrate. 



