TRANSACTIONS OF THE SECTIONS. 459 



when placed on the middle point of the surface, or on the front 

 of the apex, than when placed elsewhere. 



The right wing being held aside, so as to admit of the right 

 auricle being seen, this was observed to swell during the con- 

 tinuance of the ventricles in their hardened state, and to dimi- 

 nish its size from the instant in which their flaccidity commenced, 

 its degree of contraction being, however, inconsiderable. The 

 contraction of the appendix was preceded by that of the rest of 

 the auricle, and followed by the instantaneous movement and 

 hardening of the ventricles. The contraction of the different 

 parts of the auricle was successive, commencing at the venae 

 cavae, and terminating at the appendix, of which last the con- 

 traction was much more sudden and distinguishable than that of 

 any other part. 



The heart in this subject continued to beat for an hour, when 

 the motions in all its parts ceased, and nearly at the same time ; 

 both auricles and both ventricles remaining distended, soft, and 

 full of blood. The heart, separated from the body, was thrown 

 into tepid water, where it remained, soft, and without motion, 

 and had lost the power of contracting itself. 



2. A rabbit having been strangled, the heart was exposed 

 while still beating. In about 10 minutes the left ventricle 

 ceased to move, and had contracted itself firmly. In a minute 

 or two afterwards all motion was at an end in the left auricle, 

 which was also contracted. The right ventricle continued its 

 movements for 45 minutes, and during its contraction the apex 

 of the heart was drawn a little to the right side. The right 

 auricle continued to possess motion for an hour and three quar- 

 ters ; and for the last 20 minutes its contraction proceeded 

 slowly, and with a motion apparently vermicular, over its sur- 

 face ; always commencing at the part contiguous to the venae 

 cavae, and ending at the appendix. The right auricle and ven- 

 tricle contained each some blood when their motions ceased ; 

 but, the heart having been thrown into tepid water, they gra- 

 dually expelled their contents, assuming, as those of the left 

 side had done, a firm and contracted state. 



The difference of the states in which the hearts were found, 

 after their motions had ceased, in the last two experiments, is 

 remarkable, and appears to admit of the following explanation^ 

 In the last experiment, in which no means were employed to 

 continue respiration, the left side of the heart soon ceased to 

 move ; because a continuance of the functions of the lungs, as 

 proved by the experiments of Bichat, is necessary to the main- 

 taining of its actions. The firmness of its contraction shows, 

 that although its ordinary motions had ceased, it still retained 



