62 



246. 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. 



247. Add barium chloride. A white, heavy precipitate 

 insoluble in nitric acid. Sulphates are present. 



248. Add nitric acid and molybdate of ammonia and 

 heat. A yellow precipitate indicates the presence of phos- 

 phates. 



249. Test with Fehling-'s solution, and boil. Red, 

 cuprous oxide indicates a reducing sug-ar — dextrose. 



250. 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. 



251. Detection of paraglobulin (fibrinoplastin, or serumglobulin). Pass 

 some CO through a beaker of dilute serum for 20 minutes or more. (The CO 

 may be generated by the action of dilute hydrochloric acid upon small pieces 

 of marble in a jar and the gas conveyed to the beaker). Let the precipitate 

 settle. It is paraglobulin. Decant and, after washing with water, dissolve 

 some of it in a little dilute saline solution, use Piowtrowski's test and prove it 

 a proteid. 



252. Take equal quantities of blood and ether in a test- 

 tube. Shake thoroughly and let the ether separate. Then 

 pour the ether into a watch-glass or evaporating dish and 

 when evaporated examine for globules of fat. 



253. Evaporate a little blood to dryness in a crucible or 

 evaporating dish. Raise the temperature to red heat to con- 

 vert the blood to ash. When cool add a little nitric acid, heat, 

 dilute with water and filter. Make the following tests with 

 the filtrate : 



254. To a small portion of the filtrate add a little sulpho- 

 cyanide of potassium. A red color indicates iron. 



255. To another portion add a little ammonium molyb- 

 date solution. A yellow precipitate, after allowing the mix- 

 ture to stand for some time, indicates phosphates. 



256. To another portion add a little silver nitrate solu- 

 tion. A white, cloudy precipitate indicates chlorides. 



257. Examination of blood with a spectroscope. With a 

 small direct vision spectroscope focus on the sky or bright 

 light until the spectrum shows clearly. Narrow the slit un- 



