Royal Society. 67 



and find that the laws which govern the phaenomena are established, 

 we cannot but entertain hopes that a door has been opened through 

 which may at length be discovered the precise distinction betweei^ 

 two agents which in many respects so greatly resemble each other 

 in their effects and in their laws of acting. Such being our opinion 

 of the results obtained by Mr. Faraday, we can have no hesitation 

 in recommending most strongly the publication of his paper in the 

 Transactions of the Royal Society. 



(Signed) S. H. Christie. 



J. BoSTOCK. 



. Dr. Davy's Paper on the Torpedo, was then read in continuation. 



April 12. — The reading of Dr. Davy's Paper, entitled, " An Ac- 

 count of some experiments and observations on the Torpedo," was 

 resumed and concluded. 



The late Sir Humphry Davy gave an account, in a paper pub- 

 lished in the Philosophical Transactions for 1829*, of some experi- 

 ments which he made on the Torpedo, with the view of ascertaining 

 how far its electricity is analogous to that of the voltaic, or other 

 galvanic batteries; but the results he obtained were altogether of a 

 negative kind. He was prevented by the declining state of his health 

 from prosecuting this inquiry, which he was still ardently bent upon 

 completing, and which he requested his brother would carry on after 

 his death. The author, accordingly, when at Malta, being in a fa- 

 vourable situation for obtaining living torpedos, made the series of 

 experiments which are related in the present paper. They entirely 

 confirm those of Mr. Walsh made in 1772, and which established 

 the resemblance of the agency exerted by this fish to common elec- 

 tricity ; and they also prove that, like voltaic electricity, it has the 

 power of giving magnetic polarity to steel, of deflecting the magnetic 

 needle, and also of effecting certain chemical changes in fluids sub- 

 jected to its action. Needles perfectly free from magnetism were 

 introduced within a spiral coil of copper wire, containing about 180 

 convolutions ; the whole coil being an inch and a half long and one 

 tenth of an inch in diameter, weighing only four grains and a half, 

 and being contained in a glass tube just large enough to receive it. 

 On the electric discharges from a vigorous torpedo being made to 

 pass through the wire during a few minutes, the needles were ren- 

 dered strongly magnetic. The same influence transmitted through 

 the wires of the multiplier produced very decided deflexion of the 

 needle ; the under surface of the electrical organ of the torpedo, 

 corresponding in its effect to the zinc plate of the simple voltaic 

 circle, and the upper surface corresponding to the copper plate. Na 

 effect of ignition could l)e perceived when the discharge from the- 

 torpedo was made to pass through a silver wire one thousandth of 

 an inch in diameter : nor could unequivocal evidence be obtained of 

 the production of sparks on interrupting the circuit ; the slight lu- 

 minous appiarances wliich occurred being probably of the same kind 



• Sir n. Davy "8 Paper on the Torpedo will he found in Phil. Mag. un4 

 Amiai.s, vol. vi. p. 81. 



K 2 



