4-10 Sig. Nobili and Antinori ofi the Eleclro-motive Force 



The physiological effects {Exp. Res. 22.56,&c.) consist, as is 

 well known, in the shocks or contractions of the muscles, the 

 acrid and acidulous taste on the tongue, and the light befoi'e 

 the eyes*. For obtaining these effects, it is absolutely neces- 

 sary that the electricity should penetrate into our organs ; 

 these latter belonging to humid conductors. This path, as we 

 have seen, is very difficult for the new currents; nevertheless, 

 the frog put into the circuit of our electro-dynamic spirals, ar- 

 ranged around the lifter of our magnet, was powerfully con- 

 vulsed each time that the lifter was separated or attached {Exp. 

 lies. 56.). The experiment is beautiful and instructive; beautiful, 

 because of the energetic convulsions produced apparently by 

 the immediate action of the magnet ; and instructive, because 

 it confirms the fact of the passage of these currents through 

 humid conductors, and because also it shows that the frog is 

 in all cases the most delicate galvanoscope f . This is a fit oc- 

 casion to say what I have already said elsewhere, relative to 

 the discovery of Dr. Seebeck, that it was not necessary that 

 Oersted's discovery and the following one of the galvanometer 

 should be known, to arrive at the knowledge of the thermo- 

 electric currents :{:. The frog properly prepared was suffi- 

 cient for the purpose, and the same animal would have been 

 quite sufficient to discover the new currents of Faraday. 

 Although it is not by this road that these two discoveries 

 have been arrived at, still it is not less true that they might 

 have been made by the simple assistance of this interpreter, 

 which astonished Europe in the first times of galvanism. 



6. Magnetism of Rotation {Exp. Res. 81 to 139 : 149 to 169 : 

 181 ^0 192: 217^0 230: 244 ^o 254-, &c.). 

 What will happen when an electro-dynamic spiral is ap- 

 proached to the pole of a bar magnet? A current is pro- 

 duced in its successive spirals, which enters upon itself in 

 consequence of the conjunction of the extremities of the 

 wire. But if in place of the spiral a mass of copper is sub- 

 mitted to the influence of the same magnetic pole, what 

 will happen? It would appear reasonable to admit in this 

 mass the same developement of currents, with this difference 

 only; that in the spiral they cannot re-enter upon themselves 

 in each spire; whilst in the mass the currents will re-enter 

 directly into themselves, on the circle or zone of matter in 

 which they are determined by the influence of the magnet: 

 these currents, in the present state of science, cannot be con- 



[• The sensation on the tongue and the light before the eyes I believe 

 J have obtained. See (56) of my papers.— M. F.] 

 t Bib. Univ. xxxvii. 10. X Ibid, 



sidered 



