The Serum to be Tested 



289 



Human heart muscle, free from pericardial fat was ground in a meat chopper 

 and covered with absolute alcohol in a wide-mouthed bottle. After forty-eight 

 hours the alcohol was decanted on to a dinner plate and the tissue expressed 

 between layers of cheese cloth. The expressed juice was added to the alcohol 

 and the tissue returned to the bottle. The alcohol was evaporated by means of 

 a current of air from an electric fan and the residue scraped up with a bone 



.*' 



.%fJ 



D. 



Fig. 99.— The Kei- 

 del tube for collecting 

 blood (Manufac- 

 tured by the Steele 

 Glass Co., of Phila- 

 delphia). 



Fig. 100. — Parts of the Keidel tube. E 

 is the vacuum bulb which is attached to the 

 needle by a piece of rubber tubing (D) ; the 

 glass tube (B) covers the needle and the 

 whole is sterilized (Kolmer). 



spatula and added to the tissue. Three volumes of absolute alcohol are then 

 added and the closed bottle kept at room temperature for two weeks. At the 

 end of this time the alcoholic extract was filtered off and to each 8 cubic centi- 

 meters was added 2 cubic centimeters of a 2 per cent, solution of cholesterol in 

 absolute alcohol. 



19 



