' OV GALVANISM. 213 



thereby the faculty of throwing the legs and thighs of a frog 

 into convulfive movements, according to the difcovery of Mr. 

 Ritter; I propofed to him, to pafs the flream of fluid from a 

 powerful eledtrical machine through thefe fame wires of plati- 

 na, in order to obferve, whether it would have the fame efFe6l 

 on them as the fleam from the galvanic pile. We employed and expofed to 



... , . r • , V- . /• . *^ •' the ftream of a 



the plate machme or 35 inches diameter, and of the new con- plate machine 

 ftrudlion, defcribed in the Journal de Pliyfique for June, 1791 , ^°'' ^^^^ ''"^e 

 vol. 38, (or Philofophical Journal, quarto fefies. No, 2.)* but more * 

 Having pafTed the flream from it through the wires of platina, weakly. 

 held a quarter of an inch from the condu6tor, for the fpace of 

 five minutes, we touched with them the crural nerves of a 

 frog prepared in the ufual manner, and obferved immediately 

 the fame convulfive movements in its legs and thighs, though 

 not fo flrong as in the preceding experiment. Thfs lefs power- 

 ful effeft of the flream from the machine perfectly anfwered my 



! expectations, fince my experiments in November, 1801, de- 

 fcribed in my letter to Mr. Volta, fhewed me that the flream 



I from the machine had not more than five fixths of the velocity 

 or flrength of the flream fet in motion by a fimilar pile. 



We then repeated the experiment, keeping the wires of The experiment 



\ platina in contact with the conductor of the machine, while we the w^reThavng 



pafTed the flream through them. Then holding the wires one been kept in 



in each hand, as in the preceding experiment, and in contact ^ ndu^or- 



with the two crural nerves, but keeping their oppofite extre- when the lenfi- 



mities feparate, their effeft on the fame frog, the fenfibility o{^^^^ °jjj^^ ^''^ 



-which was greatly weakened, was fcarcely perceptible : but weakened, the 



on bringing: the upper extremities of the wires together, while ^^^"^.^^ 



f' " ^'^ . I 1 1 fcarcely percep- 



the lower remained in contact with the crural nerves, we no- tibe, 



ticed very llriking convulfions in the legs of the frog, every ""'^^^ the upper 



. .. I.. I A>-iri- extremities of 



time the extremities were made to touch. A little leal ing t^g ^jres were 



wax, which had been ufed to keep the wires of platina infu- bro ght into 



lated when held to the conductor, and which flill adhered to^y^^^ * ,jjj.jg 



one of the upper ends, rendered the experiment flill more fealing wax pre- 



evident; for when we brought thefe ends together in fuch a Y.^l^^^^^^f'^f' 



manner, that a little of the wax prevented tlieni from being the wires, no 



in perfect conta6t, the legs of the frogs exhibited none of the ^f'^ ^^°^ 

 » place* 



• It is a machine, that produces pofitive and negative eleftricity, 

 like the pile of Volta. Delametherie. 



convulfive 



