Miscellanies. 187 
equally distinguished for ri rece 06.8 talents, and for the purity 
of his character.— Bib. 
3. Experiments ind 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 ina 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 sufficient 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 aninchdiameter. No 
well marked spark was obtained when the circuit was interrupted >. 
the slightly luminous appearances which were then observed being 
Me See Bibl. Univer. 1829, Tome xli. p- 99. 
