IN MAGNETISM AND ELECTRICITY. 
101 
simultaneously with the small amount manifested in the permanent magnet, is the 
constant accompaniment of, at least, a correlative amount of electricity evolved from the 
magneto-electric machine, either all at once, in a large quantity, or by a continuous 
succession of small quantities (45, 46), — the power which the metals (but more particu- 
larly iron) possess of accumulating and retaining a temporary charge of electricity, or of 
magnetism, or of both together (according to the mode in which these forces are viewed 
by physicists), giving rise to the paradoxical phenomena which form the subject of this 
research*. 
§ 2. On a new and powerful Generator of Dynamic Electricity. 
55. The fact that a large amount of magnetism can be developed in an electro-magnet 
by means of a permanent magnet of much smaller power having been established, and as 
from the first series of experiments (Table I.) it was shown that definite quantities of 
magnetism are accompanied by the evolution of proportionate quantities of dynamic 
electricity, and since an electro-magnet, when excited by means of a voltaic battery, 
possesses all the properties of a permanent magnet, it appeared reasonable to suppose 
that a large electro-magnet excited by means of a small magneto-electric machine could, 
by suitable arrangements, be made instrumental in evolving a proportionately large 
quantity of dynamic electricity, notwithstanding the pulsatory character of the electricity 
transmitted through the wires surrounding the electro-magnet. 
56. Two magnet-cylinders, of similar construction to the one already described (9) 
* Since the publication of the abstract of this paper in the Proceedings of the Koyal Society, my attention 
has been directed to several accounts of experiments in -which electro-magnets, excited by means of magneto- 
electric machines, have been made to sustain considerable weights. The most important of these accounts 
which have come under my notice, is one contained in Sillihan’s Journal of Science for 1845, vol. xlviii. p. 393, 
in which it is stated that Dr. Page, by means of a magneto-electric machine, made an electro-magnet sustain 
a weight of 1000 lbs. 
Another account to which I have been referred, is contained in a Treatise on the Electric Telegraph, by 
M. l’Abbe Moigno, Paris, 1849, in which it is stated (page 15, p. 72 in the second edition) that the Abbe's 
Moigno and Raillakd, by means of a small machine, made an electro-magnet sustain a weight of 600 kilogrammes. 
In neither of these accounts, however, does any direct comparison appear to have been made between the 
sustaining-power of the permanent and the electro-magnets, as no mention is therein made of the sustaining- 
power of the permanent magnets, nor are they (the permanent magnets) specifically mentioned. 
In a brief notice of my experiments which appeared in ‘ Les Mondes ’ of September 6th, 1866, of which 
Journal M. l’Abbe Moigno is the editor, he gives what professes to be a quotation from his ‘ Traite de Tele- 
graphic Electrique,’ in which he has introduced a statement specifying the sustaining-power of the permanent 
magnets used in his experiments, although no such statement is to be found in the treatise from which the quo- 
tation is taken. 
Another discrepancy with reference to the account of Moigno’s experiments also occurs in an article on 
“Wilde’s Magneto-electric Machine,” in the Quarterly Journal of Science for October 1866, in which the 
writer would seem to have mistaken a small electro-magnet (used only as an adjunct to a magneto-electric 
machine, and which Moigno states would only support a few grammes) for the permanent magnets which excited 
the electro-magnet ; and from this error it is made to appear that the permanent magnets used by Moigno 
would only sustain a few grammes. 
