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warn againft the nerve being divided near 
the mufcle, as then either the movements 
do not take place at all, or if they do, are 
fcarcely perceptible, and only for a moment. 
Sometimes I have wounded the nerve of 
the wing, whilft it remained attached to 
the body to fee what would happen, and 
it has conffantly proved inimical to the 
experiment. Sometimes the wing has 
remained entirely motionlefs ; in this 
cafe, the nerve lofes the power of conduct¬ 
ing the eleCtric fluid. But why does it 
lofe it? To anfwer this queftion, one 
fhould be acquainted with the ultimate 
ftruCture of the nerves, their fprings and 
mechanifm ; but we are far from being 
arrived at this point, and perhaps lliall 
never attain it. 
In frogs, the cafe is widely different. 
Whether the nerves are left attached to 
the fpine, or feparated from it, the mo¬ 
tions conftantly occur; and one cannot 
perceive 
