AND ANIMAL LIFE. 275 



CCXCVI. The correctness of WILSON PHILIP'S 

 explanation rests on the supposition, that nearly 

 one-third of the blood of the system is prevent- 

 ed from flowing to the heart ; but if the opium 

 influenced merely the quantity of the vital fluid, 

 and did not diminish the irritability of the heart, 

 by being carried to this organ by the circulation, 

 its contractions would continue much longer, and 

 would be less sensibly retarded by the applica- 

 tion of such means. 



CCXCVI I. Galvanism is one of the most pow- 

 erful stimulants we possess, and when its mode 

 of action on the animal economy is well under- 

 stood, many diseased and deranged states of the 

 system will be alleviated or removed by its ap- 

 plication. This agent has been frequently em- 

 ployed to prove that the heart can be excited 

 through the nerves distributed to its muscular 

 substance ; and the following Experiments will 

 show that this effect is as readily produced by 

 applying the positive or negative wire to the 

 vein, or almost every other part of the body, as 

 to the nerves themselves. In these Experiments 

 two troughs, each of 50 two-and-a-half inch plates, 

 were used. Adult rabbits were always employed. 



EXPERIMENT I. 



The negative side of the battery was connected with the 



heart, and the positive with the jugular vein. The heart 



was immediately affected ; its enfeebled contraction was 



changed into an imperfect vermicular motion. The posi- 



S 2 



