232 QUANTITATIVE ANALYSIS. 



ture (30-35 cc. of nitric acid), or oxidize according to the 

 method of A. Neumann, page 215. 



4. For the sulphur determination fuse the same quanti- 

 ties with the oxidizing mixture, or oxidize first with nitric 

 acid, as in the case of meat. 



5. For the determination of fat 20 to 25 cc. of the blood 

 are weighed off (less may also be used), poured into five 

 times its volume of absolute alcohol contained in a wide- 

 necked glass-stoppered bottle, and repeatedly shaken. (The 

 pipette must not be rinsed here. It is best to fasten it in a 

 clamp and let it stand for some time, when the blood gradu- 

 ally collects and may be blown out. If the blood has been 

 weighed [in a large weighing-glass], then rinse out the glass 

 with alcohol.) Filter next day through a dry filter, wash 

 once with absolute alcohol, and let the filter dry. Evaporate 

 the alcoholic solution to dryness, dissolve the residue in 

 ether, place the ether extract in the Soxhlet flask and the 

 filter with its contents (or the coagulum alone, if it can be 

 separated from the filter without any loss) in the extraction- 

 thimble, and determine the fat in the usual manner. 



6. Determination of Iron. Evaporate to dryness on 

 the water-bath between 15 and 20 g. (or cc.) of blood in a 

 platinum or porcelain dish and cautiously carbonize until 

 vapors cease to be evolved. The residue is then warmed 

 with dilute hydrochloric acid free from iron, the solution 

 filtered through a filter containing no iron, and the filter 

 washed with water until the filtrate no longer has an acid 

 reaction. The filter with the carbon is dried, and the dish 

 also. The filter is then placed in the dish and ignited until 

 the carbon is completely burned. The hydrochloric acid 

 solution is then poured into the dish, about twenty drops of 

 dilute sulphuric acid are added, the contents of the dish are 

 evaporated to complete dryness on the water-bath and 

 ignited. Cover the residue remaining after ignition with a 



