424 PHYSIOLOGICAL CHEMISTRY. 



method proper on p. 389. Inasmuch as i c.c. of the uranium solu- 

 tion should precipitate 0.005 g ram of PaO 5 , exact ly 20 c.c. of the 

 uranium solution should be required to precipitate the 50 c.c. of the 

 standard phosphate solution. If the two solutions do not bear this 

 relation to each other they must be brought into the proper relation 

 by diluting the uranium solution with distilled water or by increas- 

 ing its strength. 



Starch Iodide Solution. 1 Mix o'.i gram of starch powder with 

 cold water in a mortar and pour the suspended starch granules into 

 75-100 c.c. of boiling water, stirring continuously. Cool the starch 

 paste, add 20-25 grams of potassium iodide and dilute the mixture 

 to 250 c.c. This solution deteriorates upon standing, and therefore 

 must be freshly prepared as needed. 



Starch Paste. 2 Grind 2 grams of starch powder in a mortar 

 with a small amount of water. Bring 200 c.c. of water to the boil- 

 ing-point and add the starch mixture from the mortar with con- 

 tinuous stirring. Bring again to the boiling-point and allow 7 it to 

 cool. This makes an approximate i per cent starch paste which 

 is a very satisfactory strength for general use. 



Stokes' Reagent. 8 A solution containing 2 per cent ferrous 

 sulphate and 3 per cent tartaric acid. When needed for use a small 

 amount should be placed in a test-tube and ammonium hydroxide 

 added until the precipitate which forms on the first addition of the 

 hydroxide has entirely dissolved. This produces ammonium fer- 

 rotartrate which is a reducing agent. 



Suspension of Manganese Dioxide. 4 Made by heating a 0.5 

 per cent solution of potassium permanganate with a little alcohol 

 until it is decolorized. 



Tanret's Reagent. 5 Dissolve 1.35 grams of mercuric chloride 

 in 25 c.c. of \vater, add to this solution 3.32 grams of potassium 

 iodide dissolved in 25 c.c. of water, then make the total solution up 

 to 60 c.c. with distilled water and add 20 c.c. of glacial acetic acid 

 to the mixture. 



Tincture of Iodine. 6 Dissolve 70 grams of iodine and 50 grams 

 of potassium iodide in i liter of 95 per cent alcohol. 



Toison's Solution. 7 This solution has the following formula : 



1 Fehling's method, page 367. 



2 Experiments on starch, page 44. 



3 Haemoglobin, page 203. Hsemochromogen, page 202. 



4 Kriiger and Schmidt's method, pages 374 and 406. 



5 Tanret's test, pages 98 and 317. 



6 Smith's test, -pages 155 'and 325. 

 " Blood counting," page 212. 



