606 PHYSIOLOGICAL CHEMISTRY 



Sahli's Reagent. 1 This reagent consists of a mixture of equal parts 

 of a 48 per cent solution of potassium iodide and an 8 per cent solution of 

 potassium iodate. 



Salted Plasma. 2 Allow arterial blood to run into an equal volume 

 of a saturated solution of sodium sulphate or a 10 per cent solution of 

 sodium chloride. Keep the mixture in the cold room for about 24 

 hours. 



Schweitzer's Reagent. 3 Add potassium hydroxide to a solution of 

 copper sulphate which contains some ammonium chloride. Filter off 

 the precipitate of cupric hydroxide, wash it, and bring 3 grams of the 

 moist cupric hydroxide into solution in a liter of 20 per cent ammonium 

 hydroxide. 



Scott-Wilson Acetone Reagents. 4 (a) Mercury Reagent. This 

 reagent is made up as follows: Mercuric cyanide 10 grams, sodium 

 hydroxide 180 grams, water 1 200 c.c. The solution is agitated in a flask 

 and 400 c.c. of a 0.7268 per cent solution of silver nitrate slowly run in. 

 Let stand three days and decant supernatant liquid. 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. 



(b) Standard Potassium Thiocyanate Solution. Make up an approxi- 

 mately o.i per cent solution of potassium thiocyanate and standardize 

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

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



(c) Acid Mixture. Nitric acid 40 parts, sulphuric acid 5 parts, and 

 water 55 parts. 



(d) Permanganate N/$ Solution. Dissolve 6.324 grams of potassium 

 permanganate in water and make up to a liter. 



SeliwanofPs Reagent. 5 Dissolve 0.05 gram of resorcinol in 100 c.c. 

 of dilute (1:2) hydrochloric acid. 



Sherrington's Solution. 6 This solution possesses the following 

 formula : 



Methylene-blue o . i gram. 



Sodium chloride 1.2 grams. 



Neutral potassium oxalate 1.2 grams. 



Distilled water 300 . o grams. 



Silver Nitrate Solution. 7 Dissolve 29.042 grams of silver nitrate in 

 i liter of distilled water. Each cubic centimeter of this solution is 



1 Determination of free acid, p. 164. 



2 Experiments on blood plasma, p. 268. 



3 Schweitzer's solubility test, p. 49. 



4 Determination of acetone and acetoacetic acid, pp. 284 and 536. 



5 Seliwanoff's reaction, pp. 35 and 447. 

 > "Blood counting," p. 305. 



7 Volhard- Arnold method, p. 556, Mohr's method, p. 558, and Dehn-Clark method, 

 P- 558. 



