446 Additmial Notes, 



Galvanism. 

 Gi/mnoius Electriciis^ Torpedo, S(c. p. 28. 



The Gymnoius Electricus is a native of the river of Su- 

 rinam, in South-America. Those which were carried to 

 England about eight years ago were about three or four 

 feet long, and gave an electric shock, by putting one finger 

 on the back, near its head, and another of the opposite 

 hand into the water near its tail. In their native country 

 they are said to exceed twenty feet in length, and kill any 

 man who approaches them in an hostile manner. It is not 

 only to escape its enemies that this surprising power of the 

 fish is used, but also to take its prey; which it does by be- 

 numbing them, and then devouring them before they have 

 time to recover, or by perfectly killing them at once ; for 

 the quantity of the power seems to be determined by the 

 will of the animal; as it sometimes strikes a fish twice before 

 it is sufficiently benumbed to be easily swallowed. 



The organs productive of this wonderful accumulation of 

 electric matter have been accurately dissected and described 

 by Mr. J. Hunter, Pliilos, Trans, vol. Ixv. and are so 

 divided by membranes as to compose a very extensive sur- 

 face, and are supplied with many pairs of nerves, larger than 

 any other nerves of the body: but how so large a quantity is 

 so quickly accumulated as to produce such amazing effects 

 in a fluid ill adapted for the purpose, is not yet satisfactorily 

 explained. The Torpedo possesses a similar power in a less 

 degree, as was shown by Mr. Waich, and another fish 

 lately described by Mr. Paterson. Fhil. Trans, vol. Ixxvi, 

 Botanic Gardc?iy Part I. Canto i. p. 12, note. 



Late Discoveries in Galvanism, p. 30. 



Four epochas may be observed in the history of Galvan-* 

 ism, each of them distinguished by the developement of im- 

 ])ortant facts. The frst was formed by the publication of 

 the fundamental Galvanic fact, viz. the production of mus- 

 cular contraction by the application of metals to the nerves 

 and muscles of animals, and which was entirely limited to 

 organized bodies. The second may be derived from the dis- 

 covery of the Galvanic influence in inorganic matter. The 



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