1904.] On the Action of the Venom of Bungarus cceruleus. 109 



II. We found that Calmette's anti-venomous serum in quantities 

 sufficient tq protect rats against ten minimum-lethal doses of Cobra 

 venom, in the same quantities was quite powerless to protect these 

 animals from 'similar doses of Krait venom. 



III. We ' studied the condition of various nerve terminals, both in 

 animals that die after poisoning by Krait venom and in nerve muscle 

 preparations from the frog, and found that the integrity of these nerve 

 ends was invariably involved at a comparatively early stage in the 

 poison. 



IV. The blood was carefully examined and no evidence of ante- 

 mortem clotting or intravascular haemolysis was discovered. ..,, 



V. We examined the action of Krait venom when its solution was 

 perfused through the isolated vessels and heart, respectively, of the 

 frog. We found that this venom, while resembling in action that of 

 Cobra venom, differs greatly in the degree of constriction of vessels 

 and enhancement of ventricular contraction produced. Cobra venom 

 exercises an action in these directions many times greater than that of 

 Krait venom. Cardio-plethysmographic tracings are shown. 



VI. Studying the manner in which the vital functions of mammals 

 (rabbits, cats, and dogs) were influenced when exposed to the action of 

 this venom, we show by means of kymographic and plethysmographic 

 tracings that the vaso-motor centre is strongly affected, a suspension 

 of the activity of this centre, as shown by the great splanchnic dilata- 

 tion, rapidly ensuing after its transient stimulation. There are also 

 indications of a feeble cardio-inhibitory action. The experiments and 

 illustrative tracings likewise show that death is brought about by 

 destroying the activity of the respiratory centre. 



VII. From these results the conclusion may be arrived at that while 

 the symptoms produced by Krait poisoning are similar bo those of 

 Cobra poisoning, they differ so much in relative degree as to render it 

 doubtful if they can properly be spoken of as identical. 



