1904.] 



Pharmacology of Indian Cobra Venom. 



185 



attendant on the use of the latter drug in Cobra poisoning are pointed 

 out. 



3. The study of the action of Cobra venom on the frog heart in situ was 

 next taken up, by means of a number of devices, which included the 

 direct application of the poison to the medulla oblongata, which was 

 exposed for the purpose. 



4. Perfusion of the mammalian heart was carried out with solutions of 

 Cobra venom of various strengths. — The isolated heart was perfused 

 through its coronary vessels with a nutrient fluid, in which the venom 

 was dissolved. Cats' and rabbits' hearts were used. 



5. By means of kymographic tracings, the blood pressure, respiratory 

 movement, etc., of cobraised rabbits were recorded and studied. — The activity 

 of the vaso-motor mechanism was studied, in various stages of cobraism, 

 by stimulations of the depressor and sciatic nerves, the vagi were cut, 

 likewise at various stages, and their ends were also stimulated, in order 

 to ascertain the part played in cobraism by the vagal inhibitory 

 mechanism ; injections of a solution of sulphate of atropine were also 

 made, and the effects were observed. The author received much help 

 in this section from Drs. Sillar and Prentice. 



6. A similar set of experiments to the last was carried out on dogs and 

 cats, plethysmography tracings of intestinal volume were also included here, 

 in order to study the changes, if any, going on in the splanchnic area 

 circidation. 



7. The movements of the auricle and ventricle ivere studied in cobraised 

 cats and dogs by removing the front of the chest parietes, and attaching the 

 auricular and ventricidar walls (by means of hooks and silk threads) to levers 

 recording on a kymographic apparatus. — The blood pressure in a large 

 artery was recorded at. the same time, and intestinal volume was also 

 frequently taken by means of a plethysmograph. At various stages the 

 vagi were divided or stimulated, and the results observed. The effect 

 of giving further doses of Cobra venom with the vagi, intact or divided, 

 was also studied. The condition of the vagal nerve-ends received close 

 attention. 



8. By kymographic experiments the influence of artificial respiration on 

 the centres, nerve-ends, etc., of cobraised animals was carefully studied.. — The 

 experiments were varied in different ways. 



9. The direct action of Cobra venom on the respiratory centre of rabbits was 

 tested by applying the poison to the exposed medulla oblongata. — A stetho- 

 graph recorded the respiratory movements, and the blood pressure was 

 at the same time taken on the kymograph. 



10. Several series of experiments were undertaken to ascertain the part 

 played by the phrenic and other nerve-ends in producing the respiratory 

 complications which are seen in cobraism. 



