QUANTITATIVE ESTIMATION OF SUGAR. 119 



saccharimeter, each division above 10 = Ol grain per fluid 

 oz. Thus, 13 divisions = 1-3 grains per fluid oz. 



(e.) If more than 8 grains per oz. are present, further dilu- 

 tion is required. Full instructions are supplied with the 

 apparatus. 



4. Aceto- Acetic Acid is found in certain diabetic urines, but not 

 in all. 



(a.) To the urine add ferric chloride; a red colour is 

 obtained if this acid be present. If there is a deposit of 

 phosphates, filter. The colour disappears on heating. 



If a diabetic urine containing aceto-acetic acid be distilled, 

 this acid is decomposed, and aceton is obtained. 



5. Tests for Aceton. 



(a.) Lieben's Test. To a weak, watery solution of aceton 

 add solution of iodine dissolved with the aid of potassic iodide, 

 and then caustic soda. A yellow precipitate of iodoforin is 

 obtained. The precipitate is generally described as forming 

 hexagonal plates or radiate stars, but I have generally found 

 it to be amorphous or granular. Other substances give the 

 iodoform reaction. 



(6.) Smell the peculiar ethereal odour of aceton. 



(c.) Legal's Test. Add caustic soda solution, and then a 

 solution of freshly-prepared sodium nitro-prusside, and acetic 

 acid = a red colour. 



In all cases employ both tests, but they only give a decided 

 reaction in urine when the aceton is in considerable amount. To 

 be quite certain that aceton is present, a considerable amount of 

 the urine must be distilled, and the tests applied to the distillate. 



6. Tests for Phenol. To a watery solution of phenol 



(a.) Add ferric chloride a bluish-violet colour. 



(6.) Add bromine water = a yellow (or rather white) 

 precipitate of bromine compounds. 



