1 00 Sir T. K. Fraser and Major 11 H. Elliot. [May 10, 



venom, exerted only a very feeble action against the venom of 

 Enhydris Curtus. The venoms were mixed together and left in contact 

 with the serum in vitro for half an hour before injection. We thus have 

 obtained definite evidence of a chemical difference in the composition 

 of the two venoms, from which differences in their actions may 

 . .iiHdently be anticipated. 



Mrthods of Experiment Employed. These were : 



(1) Perfusion of the frog-ventricle with solutions of Enhydrina 



venom. 



(2) Perfusion of the vessels of pithed frogs with solutions of 



Enhydrina venom. 



(3) Kymographic experiments, in which the blood pressure, respira- 

 tory movements, etc., were recorded and studied, both before 

 and after the intravenous injection of Enhydrina venom. 



The movements of the auricle and ventricle were also studied during, 

 life by removing a portion of the chest wall, and attaching 

 levers to the heart by hooks and silk threads. Venom was 

 intravenously injected, and the results recorded and noted. 



(4) The state of the phrenic, sciatic and vagal nerve-ends was 



studied immediately on the occurrence of death in animals 

 which had received various lethal doses of Enhydrina and 

 Enhydris venoms. The secondary current was used for this 

 purpose, and the distance of the secondary from the primary 

 coil, when a muscular contraction was observed, was noted and 

 stated in millimetres. 



(5) The medulla oblongata of rabbits was exposed and Enhydrina 



venom was dropped upon the medulla at the region of the 

 respiratory centre. Eespiratory movements were recorded on 

 a drum, with the aid of a double stethograph. 



Summary of Remit*. 



(1) Enhydrina venom has no direct action on the walls of the 

 nrterioles, or at least has no action in any strength of solution which 

 could )>e present in the blood of a human victim of Sea-snake bite. 



(2) Enhydrina venom acts directly on the isolated frog ventricle,, 

 producing a tonic and stimulating effect, but this action is produced 



nly by very strong solutions (1 : 5000). The heart-beat is quickened,. 

 and the result is therefore similar to that produced by very weak 

 solutions of Cobra venom (1 : 1,000,000 or weaker). 



(3) By experimenting with the mammalian heart exposed in situ, we 

 clearly shown that Enhydrina venom has no direct action on the 



dio-mhibitory centre. This affords a striking contrast to- 

 the condition observed in Cobra poisoning. In the latter case, the 

 powerful tonic and stimulant action of the venom on the heart-muscle- 



