t>HYSlCAL AND LITERARY. 28t 



its efFedls, and particularly to {hew its in* 

 fluence upon the motion of the heart. 



I. Having inje(fted a folution of opium 

 in water into the ftomach and guts of a frog, 

 I obferved, that in little more than half ait 

 hour it leemed to have loft all power of 

 motion^ as well as feeling i for there was no 

 contrad:ion produced in the mufcles of its 

 limbs and trunk by irritating them. I 

 opened the thorax an hour after the in- 

 jediion, and found the heart, inftead of be- 

 tween 60 and 70, making only 17 pulfations 

 in a minute. The auricle, which was much 

 diftended with blood, always contradled iirft, 

 and ^fter it the ventricle, 



2. A frog continued to move its limbs, 

 and leap about for above an hour after I 

 had cut out its heart, and was not quite 

 dead after two hours and a half. 



Five minutes after taking out the heart 

 of another frog, I injeded a folution of 

 opium into its ftomach and guts. In lefs than 

 half an hour, it feemed to be quite dead ; 

 for neither pricking nor tearing its mufcles 

 produced any contra(5tion in them, or any 

 motion in the members to which they be- 

 VoL. II. N n , longed 



