20 * On the Effects of Opiian 



vided edges of the skin being drawn togetl^er 

 by slender threads. Three frogs ^were ex- 

 perimented upon. 



Twenty drops of solution were injected into 

 the stomach of one frog. The animal lived 

 four hours after. 



On examination after death, the irritability 

 was destroyed in all the voluntary muscles. 



Into another frog thirty drops were injected : 

 After 1 6 minutes the animal was convulsed ^ 

 the extremities below the knee w^hich had no 

 communication with the superior part of the 

 body, except by the undivided ischiatic nerves, 

 were likewise affected by convulsions, and in 

 two hours and ten niinutes, the animal was 

 dead. 



The ligatures which united the divided edges 

 of the skin of the thighs were then separated, 

 and the ischiatic nerves exposed ; they were 

 compressed ; the compression of the nerve on 

 one side, produced a slight contraction, in one 

 of the muscles in the lower part of the limb, 

 but when repeated, no contraction followed ^ 

 the compression of the nerve of the other limb, ' 

 occasioned no contractions. . The irritability in 

 all the other, muscles was exhausted. 



Into a third frog, prepared in like manner, 

 forty drop's were injected: After 15 minutes* 

 the animal was convulsed ; after the space of 



