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Experiment LX. 
Having opened the abdomen of a live 
frog and expofed the crural nerves, I palled 
under one of them the flat handle of my 
fcalpel, and applied fome opium upon it. 
In four minutes the animal loft the power 
©f moving the leg. During this fpace of 
time, the exciter produced the ordinary 
effects. This experiment, which I have 
repeated more than forty times, has not, 
like many others, prefented anomalies and 
want of uniformity. At every repetition, 
the frogs have conftantly loft their power 
over the leg, and the exciter has produced 
motion. 
In this cafe, it was neceflary to coat 
either the nerves or the mufeles. 
Why opium ftiould, under certain cir- 
cumftanees, a<ft upon the nerves and not 
in others, is what I am altogether igno¬ 
rant of, and perhaps the beft informed 
phyfiologifts are not much better inftructed 
on this head. Are 
