URINE 537 



tity of an abnormal urine high in acetone) into flask A, together with 25 grams 

 anhydrous sodium sulphate and i c.c. of concentrated sulphuric acid. Ten c.c. 

 of 40 per cent sodium hydroxide solution are placed in flask C and 10 c.c. or more 

 of the mercuric cyanide solution 1 in the Erlenmeyer flask E, the tube D being 

 arranged so as to dip beneath the surface of the reagent. 



If more than 0.4 mg. of acetone is present in the amount of urine taken, the 

 quantity of reagent should be proportionately increased. It is desirable to make 

 a test to determine the approximate amount of acetone bodies as outlined under 

 the Folin-Hart method (page 534). Connect up the apparatus closing B with a 

 glass-rod plug, and light the burners under A and C. The sodium hydroxide 

 solution in C must boil before the urine in A as otherwise condensation would 

 take place in C. Keep the hydroxide solution just at the boiling point and allow 

 A to boil briskly. Note the first appearance of turbidity in flask E and distil for 

 five minutes from that time. Remove the plug at B and extinguish the burners. 

 Remove tube D and rinse with distilled water into flask E. Allow to stand for 

 ten minutes. 



Filter off the precipitate on an asbestos mat in a Gooch crucible. The pores 

 of the filter should have been partially closed by filtering a suspension of talc 

 through it. If the first portions of the filtrate are not clear, pass them through 

 the filter again. Transfer any precipitate adherent to the sides of the flask to the 

 filter with the aid of water and wash the filter thoroughly with water. Transfer 

 the asbestos and precipitate to an Erlenmeyer flask by means of a glass rod. 

 Any precipitate adherent to the crucible or glass rod is washed into the flask with 

 a jet of "acid mixture" (nitric acid 40 parts, sulphuric acid 5 parts and water 55 

 parts). About 10 c.c. of this acid mixture should be used altogether. Then add 

 i c.c. of N/5 potassium permanganate solution. 2 Boil until the brown color given 

 by the permanganate has completely disappeared. This should occur in one to 

 two minutes but if the decolorization occurs more rapidly (a few seconds), 

 insufficient permanganate has been added and another cubic centimeter or so 

 should be run in so that the color is not dispelled on two minutes boiling. Clear 

 with a few drops of yellow nitric acid. 



Cool the completely decolorized solution under the tap and add 2 c.c. of a 

 saturated solution of ferric alum. Titrate with standard potassium thiocyanate 

 solution 3 until a brownish tinge appears throughout the solution. Care should be 

 taken with the end point as the addition of several drops after the end point has 

 been reached will not perceptibly darken the color. 



Calculation. One c.c. of the thiocyanate solution if made up exactly is 

 equivalent to i mg. of Hg or 0.058 mg. of acetone. Multiply the number 

 of cubic centimeters of thiocyanate used by its equivalent of mercury in milli- 

 grams and by 0.058 to get the amount of acetone and acetoacetic acid (expressed 

 as acetone) in the amount of urine analyzed. Calculate the daily output from the 

 24-hour volume. 



1 Scott-Wilson Reagent. Dissolve 0.5 gram mercuric cyanide and 9 grams sodium hy- 

 droxide in 60 c.c. of water and then run in with constant stirring 20 c.c. of 0.7268 per cent 

 silver nitrate solution. (The silver nitrate solution is made by taking i part of standard 

 silver nitrate solution (i c.c. = 10 mg. NaCl) and 3 parts of water.) 



2 Made by dissolving 6.324 grams of potassium permanganate in water and making up 

 to a liter. 



3 Make up an approximately o.i per cent solution of potassium thiocyanate and stand- 

 ardize it against mercuric nitrate or silver nitrate. It is convenient to have the solution 

 of such a strength that i c.c. = i mg. of Hg. 



