ifn tti£ Liviag ^i^&Uiru 77 



sliQck may be given so strong, sfe.Ui^iR^C'bauRttlie 

 excitability in, (oto, without U}e least degrcef/jf 

 action b«lpg.<9yidejnced. Th^ diminution ;ol 

 action, nntl the exbauition of? >tiiii property, 

 which were evident upon the application of 

 opium to the heartj} of frogs, vide Ej(p, 

 1st, 2d & 3d, furniA therefore no argumeut 

 in favour of its sedative efFectj ;;for it |s <jlcap 

 that the same condition U abo the cops^u^jjc© 

 of the application of powerful stimuli,, ;t^ido 

 Exp. 10th, 11th, 12th & 13th, and is to be 

 explained in the above manner. The con-^ 

 dition in which the muscular fibre is left in 

 these instances, so far therefore from weaken- 

 ing the facts alledged in favour of the stimulant 

 action of opium, is rendered a very powerful 

 proof in support of it. But it must not bo 

 omitted here, to give proper weight to the 

 expQrin>er>t in which the aqtion of the heart 

 €^ the frog was encreased upon the application 

 of a very small quantity of opium, as thq 

 above explanation makes it appear in a stron gei? 

 light. For if a powerful stimulus exhausts ex- 

 citabiUty without prodnCii^ visible encreaseof 

 action, in con$equei>ce of, i|s stimulant effecti 

 ^nd if the operation of ^pium is to be attri- 

 buted to the same cause, this stimulus applied 

 in a diminished dose, a^nd in, a proj>ortion 

 suitable iq thi^ ex;citability of the partjt must 



