130 Electricity and Galvanism. 



of celebrity, Signor Valli, who commenced his researches indeed in 

 1792, only a year after the publication of Galvani's discovery, and 

 he found if the ligature were applied near the muscle it did not allow 

 the contraction to occur, but if nearer the spine it did not prevent it. 

 This was afterwards corroborated by Humboldt. I may here remark 

 that it has been since found by Prof. Matteucci, that if care be 

 taken to insulate the nerve, a ligature does arrest the contraction, as 

 well as the passage of a very weak artificial electric current. 



Little occurred during the subsequent 35 years to modify these 

 conclusions or add to their interest, repeated and extended by 

 numerous observers, especially by Humboldt, and more lately by 

 Muller. They were almost lost in the blaze of novelty surrounding 

 the vast discoveries made on the constitution of inorganic matter by 

 the magic pile of Volta, an instrument which, in the hands of our 

 late talented countryman, Sir Humphry Davy, resolved many bodies 

 previously considered simple into their constituent elements, and 

 quite changed the face of chemistry ; and still more recently, direct- 

 ed by the gifted genius and vast attainments of a Faraday, has led 

 to the discovery of new sciences, and of properties of matter before 

 undreamed of ; indeed, have promised to lay open to us the secrets 

 of the working of the invisible agents presiding over the ultimate 

 constitution of material masses. 



I cannot in this place pass over in silence the neuro-electric theory 

 of Galvani. He assumed that all animals are endowed with an in- 

 herent electricity appropriate to their economy, which electricity, 

 secreted by the brain, resides especially in the nerves, by which it is 

 communicated to every part of the body. The principal reservoirs 

 of this electricity he considered to be the fibres of muscles, each of 

 which he regarded to have two sides in opposite electric conditions. 

 He believed that when a muscle was willed to move, the nerves, 

 aided by the brain, drew from the interior of the muscles some elec- 

 tricity ; discharging it upon their surface, they thus contracted and 

 produced the required change of position. This theory was adopted 

 and defended by Prof. Aldini. 



Valli, to whose experiments I have before referred, believed the 

 neuro-electric fluid to be secreted by the capillary arteries supplying 

 the nerves, by which it became conveyed to the muscles, which he 



