42 



developed, due to the ozone liberated by the fibrin and form- 

 ing a blue color with the resin. Compare 197. 



XVI. 



200. Proteid reactions. Dilute i cc. of serum with 5 cc. 

 of normal salt solution (0.65%). Add a little litmus solu- 

 tion to color and neutralize with 0.2% hydrochloric acid. 



201. Heat another portion for the coagulation test. Use 

 the same proportions as in 200, and 



202. Apply the xanthoproteic reaction. 



203. Acidify another portion strongly with acetic acid 

 and add a few drops of a solution of ferrocyanide of 

 potassium. 



204. Apply Millou's reagent. 



205. Apply Piowtrowski's test (6). 



206. To another portion add a little alcohol. 



207. Saturate another portion (proportions as in 200) 

 with ammonium sulphate. This precipitates all of the pro- 

 teids, globulin and albumin. Filter. The filtrate does not 

 respond to any of the tests for proteids. 



208. To another portion of the diluted serum add a little 

 silver nitrate solution. A white, curdy precipitate forms, 

 soluble in ammonia but not in nitric acid. Chlorides are 

 present. 



209. Add barium chloride. A white, heavy precipitate 

 insoluble in nitric acid. Sulphates are present. 



210. Add nitric acid and molybdate of ammonia and heat. 

 A yellow precipitate indicates the presence of phosphates. 



211. Test with Fehling's solution, and boil. Red, 

 cuprous oxide indicates a reducing sugar — glucose. 



212. To a little of the defibrinated blood in a test-tube 

 add a few drops of .sulphuric acid. Stir up the solution 

 and note the peculiar odor of blood, intensified by the 

 liberation of traces of volatile acids by the sulphuric acid. 



