PLASMA. SUGAR. 147 



1. Dilute some with 10 volumes water in a tube and place 



it in the water-bath at 37 C. to hasten coagulation. 

 In about twenty minutes the fluid will turn into a perfect 

 but thin jelly. Note the quivering of the jelly when 

 the vessel is slightly shaken. Let the clot rest until 

 the next day, when it will be found to have shrunk 

 considerably. 



2. Heat some undiluted neutralised plasma slowly in the 



water-bath, and determine the temperature at which 

 coagulation first appears. Fibrinogen coagulates at about 

 56 C. 



(B) Oxalated plasma. (Decalcified plasma?) 



To blood as it flows from the blood-vessels of an animal 

 one quarter of its volume of a 1 p - c - solution of potassium 

 oxalate in normal saline is added (Arthus and Pages). The 

 blood is then centrifuged. 



To 8 cm of this plasma add 5 drops of a 2 p - c - solution of 

 calcium chloride. Place in the water-bath at 37 C. Coagula- 

 tion will take place. 



Sugar in the blood. Boil some fresh serum which has been 

 diluted with 2 volumes of water, and slightly acidulated 

 with dilute acetic acid. Coagulate the proteids com- 

 pletely, which will take five minutes; filter off as much 

 perfectly clear fluid as you can, and test a quarter 

 tubeful of the filtrate by boiling it with about 8 drops of 

 Fehling. If the reduction is not very well marked let 

 the tube stand, and at the end of twenty minutes a 

 distinct pp of sub-oxide will collect at the bottom, showing 

 the presence of a reducing sugar. 



