2Q0 PHILOSOPHICAL TRANSACTIONS. [aNNO 1793. 



wished to go further, and practise on the small members, on a muscle only, 

 and on small pieces of muscles ; which led to other new discoveries. Thus he 

 cut off sometimes a leg with the thigh of a frog, sometimes the leg only, some- 

 times the half or quarter of a leg, and having applied, as usual, to a part of the 

 lopped piece the tinsel, and to another part the silver plate, and made the 

 armour communication, he always obtained motions and convulsions. Also the 

 same with the legs or muscles, or any part of them, of a hen or other birds, 

 rabbits, &c. Hence Mr. V. infers that it is not at all necessary to make a dis- 

 charge of electric fluid between a nerve and muscle, or to transpose it from the 

 interior to the exterior of this latter by the nerve and the conducting arc, as 

 Galvani supposes : and that it is useless to sustain here an analogy with the 

 Leyden phial. 



In like manner, in another experiment, having covered the 2 thighs of a frog, 

 to exactly the corresponding parts, with 2 metal leaves, the one of silver, the 

 other of tin, he excited the contractions of the muscles, and the usual motions 

 of the legs, as soon as he made a communication between those 2 armings by 

 the conducting arc. But if 2 muscles, or 2 places in one muscle only, be 

 armed alike, viz. with 2 plates or leaves of the same metal, equal in all respects, 

 and applied alike, then connecting them by the conducting arc, there ensues no 

 convulsion, no motion. But though these effects are constant and general in all 

 quadrupeds, birds, fishes, reptiles, and amphibia, which he has tried, it is not 

 less true that worms in general, and many insects, have not the same effect. 

 He tried in vain earth-worms, leaches, slugs, and snails, oysters, and many 

 caterpillars ; being unable to excite any motion in these by small or moderate 

 sparks or discharges of artificial electricity. With some difficulty however he 

 succeeded with cray-fish, beetles, shrimps, butterflies, and fl.ies. 



Mr. V. found by his experiments that it was only the muscles subject to the 

 will that are attected by them, and not those of the viscera, that are not usually 

 so subject, as those of the heart, &c. He also shows that the electric fluid acts 

 only mediately on even the voluntary muscles ; that it is not even the inunediate 

 or efficient cause of the motion of those muscles ; and that it is the nerves only 

 that are directly affected, which again act on the muscles, viz. those more imme- 

 diately connected with them : an assertion which, he says, is rendered evident, 

 and proved by many experiments he had made on the tongue ; which led him 

 also to other curious and interesting experiments. 



Having excited tonic convulsions, and strong motions, in the muscles and in 

 the members, in both small and large animals, without laying bare any nerve, 

 by the simple application of armings of different metals to the muscles stripped 

 of the integuments, Mr. V. began to think of attempting the same thing in the 

 human subject. He easily conceived that it would succeed very well in ampu- 



