AND ANIMAL LIFE. 267 



applied. The heart contracted, but with an enfeebled 

 motion, for 45 seconds, and then ceased, but recommenced 

 in eight or ten seconds, and continued to contract five or 

 six times per minute for the space of three minutes, at 

 which time it altogether ceased. 



EXPERIMENT II. 



The preparatory steps of the operation were the same as 

 in the preceding instance. A few drops of prussic acid were 

 applied. The contractions of the heart were less frequent, 

 but appeared stronger directly on the application of this 

 poison. The results were not very decisive. In three 

 minutes from the commencement, the contraction still 

 remaining, a few drops more were applied, and the heart 

 immediately became affected; in a few seconds it gave 

 scarcely a perceptible pulsation. 



EXPERIMENT III. 



The preparatory steps having been attended to, a few 

 drops of the spirits of wine were applied. The motions of 

 the heart were more frequent for a few seconds, but as 

 soon became slow. lufusum tabaci was then employed ; 

 the contractions were quickened for a few seconds, but 

 almost immediately became much slower. Prussic acid 

 was lastly applied ; and this, like the preceding agents, 

 seemed to quicken the contractions, but in a few seconds 

 after its application the heart ceased to pulsate. 



EXPERIMENT IV. 



In this experiment infusum tabaci was employed first. 

 On its application the motions of the heart became almost 

 instantaneously slow ; they were previously strong and fre- 

 quent. While the contractions of the heart were feeble and 



