Miscellanies. 187 



equally distinguished for his extraordinary talents, and for the purity 

 of his character. — Bib. Univ. 



2. Experiments and Observations on the Torpedo ; by Dr. Davy. 

 — Sir. H. Davy, published in the Philosophical Transactions, for 

 1829,* a memoir upon some experiments which he had made on 

 the Torpedo, with a view to ascertain how far the electricity of this 

 animal is analogous to voltaic or galvanic electricity ; but his results 

 were, in general, of a negative character. The declining state of his 

 health hindered him from pursuing this research, which he had ar- 

 dently desired to complete, and which he recommended to his bro- 

 ther to continue after his death. In conformity to this wish, the au- 

 thor being at Malta, in a situation favorable for procuring living tor- 

 pedoes, made the series of experiments contained in a memoir, which 

 he read to the Royal Society of London, on the 22d of March, and 

 12th of April, 1832. They entirely confirm those made by Mr. 

 Walsh, in 1772, which established the analogy of the action exert- 

 ed by the fish with that of ordinary electricity; they prove also 

 that like voltaic electricity, this action has the power of communi- 

 cating to steel, magnetic polarity, of causing a deviation of the mag- 

 netic needle and even of producing certain chemical changes in fluids 

 which are submitted to it. Needles perfectly free from magnetism, 

 were introduced within a spiral of copper wire, containing about one 

 hundred and eighty turns. This cylinder was about one inch and a 

 half long, and one tenth of an inch in diameter : it weighed only four 

 and a half grains, and was contained in a tube of glass of a diameter 

 just suflicient to receive it. The electrical discharges of a vigorous 

 torpedo having traversed the wire for some minutes, the needles were 

 strongly magnetised. The same action having been transmitted 

 across the wires of a multiplicator, produced a decided deviation of 

 the needle ; the inferior surface of the electric organ of the torpedo, 

 corresponding as to its effects to the plate of zinc of a voltaic range 

 and the superior surface to the plate of copper. 



No effect of ignition was perceived when the discharge was pass- 

 ed through a silver wire of the thousandth of an inch diameter. No 

 well marked spark was obtained when the circuit was interrupted ; 

 the slightly luminous appearances which were then observed being 



See Bibl. Univer. 1829, Tome xli. p. 99. 



