Magnetism^ Co/iesiotif Adhesion and Viscosity. 505 



The phaenomena brouftht to light by Dr. Faraday's mode 

 of experimenting are indeed very remarkable, and they ap- 

 pear to me to have a surprising analogy with what he and 

 Thilourier effected, when operating on the gases. By the 

 resources of science, those bodies which in their normal state 

 only exhibit repulsion, were made to reveal their occult 

 power of attraction ; and in a similar manner in these new 

 experiments, bodies that had been only remarked for indif- 

 ference to magnetism, were brought within its pale. Yet the 

 instances which I have already shown, and those which are to 

 follow, will make it more than doubtful whether the two cate- 

 gories of attraction and repulsion under which bodies arranged 

 themselves in his hands, are really those that would result 

 from their normal conditions, if these could be known with 

 exactness. Thus by his experiments he considers platinum 

 as magnetic, and flint glass as diamagnetic, and they ought 

 not therefore to agree in their affinities ; yet I find that they 

 both have a remarkable attraction for lead ; crown glass too, 

 so far from having a feeble attraction for the magnet, ai^ we 

 are led to suppose from his experiments, has really a very 

 considerable affinity for it, as will be evident by the instance I 

 gave of the needle in the compass-box, which attached itself 

 2)er saltum to its glass screen on a magnet being held over it. 

 Palladium and platinum also, which Dr. Faraday considers 

 as magnetic, agree with all his diamagnetic metals with which 

 I have operateil in their attraction for glass of every kind, and 

 I find that both palladium and platinum exhibit a much 

 feebler degree of attraction for the magnetic needle than they 

 do for iron that is free from magnetism. Yet in his scale 

 crown glass ranges between palladium and platinum. 



The obscure nature of affinity cannot be better exemplified 

 than in considering these experiments, where we have afresh 

 demonstration of its universality. As no instance has yet 

 been discovered of a body existing free from repulsion, for no 

 bodies have yet been found with their molecules in close con- 

 tact, so in the present case we shall see that where attraction 

 could not be more than imagined, that that property exists in 

 considerable strength, and that it is owing to it, by the mere 

 affniity of points for points, that is of molecules lor molecules, 

 that bodies hold together with such tenacity, though each 

 point is totally inert beyond its own sphere of action ; indeed 

 so much so that the finest hair or a fragment of any substance 

 not so large as the head of a })in, has as much influence, 

 magnetically, on the various needles that have been tried, as 

 the largest mass. It is diflc'rcnt however where the electro- 

 magnet is concerned, for through its powerful influence the 



