POISON OF SOME INDIAN VENOMOUS SNAKES. 101 



they did not expand equally, but became emphysematous in 

 spots, so that the exterior of the lung assumed a nodulated 

 appearance. When the right ventricle was punctured it con- 

 tracted firmly. No further contraction took place when it was 

 irritated by the direct application of a Faradic current. The 

 blood coajTulated. 



Ihese tracings were - obtained froui a frog s heart hy means of a small 

 mercurial manometer connected with the aorta. The tracings all read from 

 right to left. 



1. Tracing obtained from the heart supplied with pure serum by means of a 

 tube in the vena cava. 



2. Tracing of the same kind, with the addition of the line A, which indicates 

 the zero of the mercury. The tracing B, given by the heart, sinks down to zero 

 during each diastole. 



3. Tracing given by the heart after it had been supplied with serum contain- 

 ing a small quantity of cobra-poison in solution. The heart makes a few 

 ineffectual attempts, but can neither contract nor relax, and remains still, in a 

 condition midway between complete systole and complete diastole. The line A 

 is the zero to which B would sink if the heart relaxed completely during 

 diastole. 



Experiment LXXIV. 

 A cannula was placed in the carotid of a dog and connected 

 with a kymographion. 



Injected some cobra-poison dis- 

 solved in water into the sciatic 

 vein. The pressure rose to 

 165, and then sank in 7 

 seconds to 135. 



