126 Messrs. T. L. Brunton and J. Fayrer on the [Jan. 22, 



contractions were regular and strong; but whenever serum containing 

 dried cobra-poison in solution (in the proportion of about two grains 

 in three fluid drachms) was introduced into the apparatus the heart 

 stopped almost immediately. As will be seen from the accompanying 

 tracing, it became partially contracted and gave one or two feeble beats, 

 but did not dilate, and then remained still, the contraction, however, very 

 slowly and gradually increasing. 



These tracings were obtained from a frog's heart by means of a small mercurial ma- 

 nometer 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 containing 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 LXXIII. 



A cat was deprived of consciousness by a severe blow on the head ; and 

 a cannula being placed in the trachea, artificial respiration was begun. 

 The thorax was then opened and the heart exposed. A solution of dried 

 cobra-poison in water was then injected into the jugular vein. At first 

 the cardiac pulsations became much quicker, but they were also strong. 

 They next became very small and rapid. Lastly, the right ventricle be- 

 came much distended, and the heart stopped. The lungs became con- 

 tracted ; and when force was used to distend them 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 contracted firmly. No further contraction took place when 

 it was irritated by the direct application of a Faradic current. The blood 

 coagulated. 





