35 ANALYSIS OF URINE. [CH. XIII. 



2. Acid mixture. Strong nitric acid 40 cc. 



Strong sulphuric acid 5 cc. 

 Distilled water 55 cc. 



3. O-2 N. potassium permanganate. 6-324 grams, of permanganate 

 dissolved in water and the volume made up to i litre. There is no necessity 

 to standardise it exactly. 



4. Standardised solution of potassium thiocyanate. Dilute 125 cc. of the 

 stock solution described in Ex. 412 to make i litre with distilled water. 

 Standardise the stock solution against standard silver nitrate as described 

 in Ex. 412. Divide 21-4 by the number of cc. of KCNS required for 10 cc. of 

 silver nitrate. 



The result = mg. of Hg per cc. of the diluted KCNS. 



5. A saturated aqueous solution of iron alum. 



Method. 



i. The distillation of the acetone. Use the apparatus shewn 

 in fig. 46. Into flask A measure an amount of urine that yields 

 between 0-4 and 2 mg. acetone. Add water to make the volume 



Fig. 46. Apparatus for the estimation of acetone. 



A. " Duro " flask. B. Solid glass rod for sealing tube. C. " Duro " flask. 

 D. Glass tube connected by rubber to condenser tube. E. Erlenmeyer flask. 

 F. Liebig condenser. 



up to about 100 cc. and then i cc. of strong sulphuric acid. Into 

 flask C place 10 cc. of 40 per cent, caustic soda and a few glass 

 beads. Into E place 20 cc. or more of the silver mercury cyanide 

 reagent (there must be at least 25 cc. to each mg. of acetone). 

 Close the tube with the glass rod B and then light the burners. 

 The soda in C must boil before the fluid in A. The soda is kept 



