EXAMINATION OF URINARY DEPOSITS. 183 



DIABETIC AND ALBUMINOUS URINE. Albumen may be 

 tested by boiling the suspected urine gently in a test-tube, 

 when it will be coagulated. As, however, a white precipitate 

 results on boiling, from an excess of earthy phosphate, it will 

 be necessary to add a few drops of nitric acid, which will re- 

 dissolve the phosphates but leave the coagulated albumen un- 

 affected. Nitric acid also will coagulate albumen. If both 

 heat and nitric acid throw down a white precipitate from urine 

 in separate portions, there can be no doubt of the presence of 

 albumen. 



The peculiar casts of urinary tubes found in the urine of 

 patients suffering from Bright' s disease, consist of fibrinous or 

 albuminous matter and entangling'blood-corpuscles, epithelium, 

 and fatty globules. 



Diabetic Sugar has the same chemical composition as that 

 contained in most kinds of fruit, known as grape sugar. Se- 

 veral tests have been proposed for its detection in urine. 



Trommer's Test is founded on the circumstance that when a 

 solution of diabetic or grape sugar is boiled with a mixture of 

 potash and sulphate of copper, the oxide of copper contained 

 in the latter is reduced to the state of suboxide, which is pre- 

 cipitated in the form of a reddish-brown or ochre-colored 

 granular powder. 



Moore's Test is made by mixing a little suspected urine with 

 half its volume of liquor potassse and boiling gently for about 

 five minutes. If sugar is present, the liquid assumes a brown 

 or bistre tint. 



The Fermentation Test is made by filling a test-tube with 

 the suspected urine, to which a little yeast has been added. 

 The tube is then inverted over a saucer containing some of the 

 urine, and set aside in a warm place for about twenty-four 

 hours. If sugar is present it undergoes the vinous fermenta- 

 tion, by which it becomes converted into alcohol and carbonic 



