142 PRACTICAL PHYSIOLOGY. [XXII. 



In diabetes mellitus, however, it occurs in considerable amount, and 

 is, of course, then quite abnormal. 



Characters of Diabetic Urine. 



(i.) The patient usually passes a very large quantity of urine, 

 even to 10,000 cc., and although the quantity of fluid is large 



(2.) The specific gravity is high 1030 to 1045 due to the 

 presence of the grape-sugar. N.B. When the quantity of urine 

 is above normal, and the specific gravity reaches 1030. suspect the 

 presence of grape-sugar. 



(3.) The colour is usually a very pale straw, from the dilution 

 not diminution of the urine pigments. The urine is often some- 

 what turbid. 



(4.) It has a heavy sweet smell, and usually froths when poured 

 from one vessel into another. 



5. Tests for Grape Sugar. In all cases remove any albumin 

 present, i.e., acidulate with acetic acid, boil, and filter. 



(a. ) Moore's Test. To urine add an equal volume of caustic soda or potash, 

 and boil the upper stratum of the fluid. If much sugar be present, a dark 

 sherry or bistre-brown colour is obtained. The colour may vary from a light 

 yellow to a dark brown (due to the formation of glucic and melassic acids), 

 according to the amount of sugar present. This is not a delicate test. 



(6.) Trommer's Test. Add to the urine one-third its bulk of 

 caustic soda solution, and then a few drops of a solution of cupric 

 sulphate, and a clear blue solution of the hydrated oxide is 

 obtained. Eoil the upper stratum of the fluid. If sugar be 

 present, a yellow or yellowish-red ring of reduced cuprous oxide 

 is obtained. 



(c.) Fehling's Solution is alkaline potassio-tartrate of copper 

 (K 2 Cu2C 4 H 4 6 ). Place some Fehling's solution in a test-tube and 

 boil it. If no discoloration (yellow) takes place, it is in good con- 

 dition. Add a few drops of the suspected urine and boil, when 

 the mixture suddenly turns to an opaque yellow or red colour, 

 which indicates the presence of a reducing sugar. 



(d.) Bottger's Test. Mix the urine with an equal volume of sodium 

 carbonate solution, add a little basic bismuth nitrate, and boil for a short 

 time. A grey or black deposit indicates the presence of a reducing sugar. 



(e.) Picric Acid. To the urine add an equal volume of a saturated watery 

 solution of picric acid, and then caustic potash. Boil, an intensely deep red 

 or reddish-brown colour indicates the presence of a reducing sugar. The 

 larger the amount of sugar, the deeper the tint. The colouration is due to 

 the formation of picramic acid. 



(/.). Phenyl-Hydrazin. Eepeat this as described in Lesson III. 

 This is a reliable test. 



