ACTION OF MAGNETS ON BISMUTH AND ANTIMONY. 
31 
little iron, nickel, or cobalt in them, or whether any of them are really so of them- 
selves, I do not undertake to decide at present ; nor do I mean to say that the metals 
of the former list are free. I have been much struck by the apparent freedom from 
iron of almost all the specimens of zinc, copper, antimony and bismuth, which I have 
examined ; and it appears to me very likely that some metals, as arsenic, &c., may 
have much power in quelling and suppressing the magnetic properties of any portion 
of iron in them, whilst other metals, as silver or platinum, may have little or no 
power in this respect. 
2294. Resuming the consideration of the influence excited by the magnetic force 
over those metals which are not magnetic after the manner of iron (2291.), I may 
state that there are two sets of effects produced which require to be carefully distin- 
guished. One of these depends upon induced magneto-electric currents, and shall 
be resumed hereafter (2309.). The other includes effects of the same nature as those 
produced with heavy glass and many other bodies (2276.). 
2295. All the non-magnetic metals are subject to the magnetic power, and produce 
the same general effects as the large class of bodies already described. The force 
which they then manifest, they possess in different degrees. Antimony and bismuth 
show it well, and bismuth appears to be especially fitted for the purpose. It excels 
heavy glass, or borate of lead, and perhaps phosphorus; and a small bar or cylinder 
of it about two inches long, and from 025 to 05 of an inch in width, is as well fitted 
to show the various peculiar phenomena as anything I have yet submitted to exa- 
mination. 
2296. To speak accurately, the bismuth bar which I employed was two inches long, 
0'33 of an inch wide, and 0 - 2 of an inch thick. When this bar was suspended in the 
magnetic field, between the two poles, and subject to the magnetic force, it pointed 
freely in the equatorial direction, as the heavy glass did (2253.), and if disturbed 
from that position, returned freely to it. This latter point, though perfectly in 
accordance with the former phenomena, is in such striking contrast with the pheno- 
mena presented by copper and some other of the metals (2309.), as to require 
particular notice here. 
2297. The comparative sensibility of bismuth causes several movements to take 
place under various circumstances, which being complicated in their nature, require 
careful analysis and explanation. The chief of these, with their causes, I will proceed 
to point out. 
2298. If the cylinder electro-magnet (2246.) be placed vertically so as to present 
one pole upwards, that pole will exist in the upper end of an iron cylinder, having a 
flat horizontal face 2\ inches in diameter. A small indicating sphere (2266.) of 
bismuth hung over the centre of this face and close to it, does not move by the mag- 
netism. If the ball be carried outwards, half way, for instance, between the centre 
and the edge, the magnetism makes it move inwards, or towards the axis (prolonged) 
of the iron cylinder. If carried still further outwards, it still moves inwards under 
