138 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
tricity failed, though the precautions before described (22.), and all others that 
could be thought of, were employed. Neither was any sensation on the tongue, 
or any convulsive effect upon the limbs of a frog, produced. Nor could char- 
coal or fine wire be ignited (133.). But upon repeating the experiments more 
at leisure at the Royal Institution, with an armed loadstone belonging to Pro- 
fessor Daniell and capable of lifting about thirty pounds, a frog was very 
powerfully convulsed each time magnetic contact was made. At first the con- 
vulsions could not be obtained on breaking magnetic contact ; but conceiving 
the deficiency of effect was because of the comparative slowness of separation, 
the latter act was effected by a blow, and then the frog was convulsed strongly. 
The more instantaneous the union or disunion is effected, the more powerful 
the convulsion. I thought also I could perceive the sensation upon the tongue 
and the flash before the eyes ; but I could obtain no evidence of chemical de- 
composition. 
57. The various experiments of this section prove, I think, most completely 
the production of electricity from ordinary magnetism. That its intensity 
should be very feeble and quantity small, cannot be considered wonderful, 
when it is remembered that like thermo-electricity it is evolved entirely within 
the substance of metals retaining all their conducting power. But an agent 
which is conducted along metallic wires in the manner described; which, 
whilst so passing possesses the peculiar magnetic actions and force of a current 
of electricity; which can agitate and convulse the limbs of a frog; and which, 
finally, can produce a spark by its discharge through charcoal (32.), can only be 
electricity. As all the effects can be produced by ferruginous electro-magnets 
(34.), there is no doubt that arrangements like the magnets of Professors 
Moll, Henry, Ten Eyke, and others, in which as many as two thousand 
pounds have been lifted, may be used for these experiments ; in which case 
not only a brighter spark may be obtained, but wires also ignited, and, as the 
current can pass liquids (23.), chemical action be produced. These effects are 
still more likely to be obtained when the magneto-electric arrangements to be 
explained in the fourth section are excited by the powers of such apparatus. 
58. The similarity of action, almost amounting to identity, between common 
magnets and either electro-magnets or volta- electric currents, is strikingly in 
accordance with and confirmatory of M. Ampere’s theory, and furnishes power- 
