"habu" venom and its serum therapy. 



157 



different sjjecies of animals; our method of studying this phenomenon 

 being as follows: 



A certain amount of venom is mixed with a 5 per cent suspension of the defi- 

 brinated blood prepared with 0.8 to 0'.9 per cent saline sohition, and allowed to 

 stand in an incubator for two hours. After this time it is left at the laboratory 

 temperature for forty-eight hours longer, after which period the result is 

 noted. The action at times would set in very slowly — occasionally not for two 

 or three days. Of course, a control is to be made to distinguish the haemolysis 

 caused by the venom from the natural laking of the blood. The solution of venom 

 must be prepared immediately before the experiment. 



The following table shows the variation of the haemolytic action with 

 different species of animals: 



Table 4. 



One cubic centimeter of a 5 per cent suspension of blood cells from different 

 animals shows minimal trace of haemolysis with the following doses: ■ 



Dog 0.0000001 



Cat 0.0000005 



Horsie 0.000001 



Pig . 0.000001 



Hen 0.000001 



Pigeon 0.000001 



Guinea pig 0.00001 



Rabbit 0.001 



Man 0.0001 



The quantities given in the above table are the minimum doses pro- 

 ducing haemolytic action, but five or ten times these amounts are neces- 

 sary to secure complete laking. The blood corpuscles of cattle, goats 

 and sheep are not affected. 



The modification of the hemolytic action by serum was studied, 

 the following experimental method being used: 



The blood corpuscles of the dag and other animals were washed four to eight 

 times in saline solution, and divided into two parts, one of which was mixed 

 with the serum of the same kind of animal and the other left free. Venom was 

 then added to each series. 



The following table shows the amount of venom required to produce 



haemolysis with the seram-free corpuscles and with those mixed with 



serum : 



Table 5. 



Guinea pig . 



Rabbit 



Horse 



Pig 



Pigeon 



Hen 



Gram. 

 0. 00001 

 0. 00002 

 0.0001 

 0. 00005 

 0. 000001 

 0. 000001 

 0. 0001 



Gram. 

 0. 0000001 

 0. 00002 

 0.0001 

 0. 000001 

 0. 000001 

 0. 000001 

 0. 00001 



6S330- 



