SUBSTANCES WHICH ACTIVATE COBRA VENOM. 



459 



of diabetes, one of pneumonia, and one typhoid) \ve were unable to 

 discover any essential difference in susceptibility. 1 



TABLE XIV. 

 SUSCEPTIBILITY OF VARIOUS SPECIES OF BLOOD TO COBRA VENOM ALONE 



c , . f TM j ci ~(f/ Amount of Cobra 



Species of Blood (1 cc.o% y Required tor Corn- 



Suspension). 



Frog 



Dog 



Guinea-pig 



Man 



Rat 



Pig 



Mouse 



Goose 



Rabbit 



Horse 



Ox, sheep, goat. 



0.00001 

 . 000025 

 000025 

 O.OOC05 

 00025 

 0.00025 

 . 00025 

 . 0005 

 0.001 

 0.001 

 not susceptible 



As a result of our extensive researches we must continue to 

 uphold the view that blood species are clearly divisible into those 

 directly susceptible to cobra venom alone and those not susceptible 

 under those conditions. This follows also from the above table. In 

 this respect our observations are at variance with the recent state- 

 ments of such excellent workers as Flexner and Xoguchi. It may 

 be well therefore once more to point out a few possibilities by which 

 this difference can be explained. Flexner and Noguchi observed 

 that, in general, after copious washing, the blood-cells were not dis- 

 solved by cobra venom, or at least were only partially dissolved. 

 In spite of repeated washing of the blood we were unable to discover 

 any decrease in susceptibility. 



If Flexner and Xoguchi insist on such a thorough washing (6-10 

 times) it appears to us that it can no longer be a question of removing 

 the serum complements. The small quantities of serum which are 

 contained in the 0.05 cc. blood employed in each tube in the test- 

 tube experiment (1 cc. of a 5T C suspension) are entirely too small, 

 according to our experience, to exert a demonstrable complement 



1 It is possible that investigations in other diseases will lead to positive 

 results. We are not in a position to apply our observations to more extensive 

 clinical material, but shall be glad to supply cobra venom for this purpose 

 to any one applying for the same. 



