Thomson's Sj/stem of Chcmistr I/. 135 



pile, consists in the particles in a combination being repolarized. 

 In a combination of particles having the same unipolarity, the 

 pile merely restores by the decomposition, the general polarity, 

 because their specific unipolarity was not changed by their 

 union ; but in combinations of opposite imipolarity it likewise 

 restores the specific unipolarity of the elements. May we con- 

 clude that, in the first case, the general repolarization takes 

 place in the same manner as the loadstone gives magnetism to 

 a small particle of steel, and that in the second, the pile con- 

 tributes by its own specific energies to restore the predominat- 

 ing poles *." " We may, therefore, at least with some proba- 

 bility, imagine caloric and the electricities to be matter desti- 

 tute of gravitation, but possessing affinity to gravitating 

 bodies. When they are not confined by these affinities, they 

 tend to place themselves in equilibrium in the universe ; the 

 suns destroy at every moment this equilibrium, and they send 

 the re-united electricities in the form of luminous rays towards 

 the planetary bodies, upon the surface of which the rays being 

 arrested, manifest themselves as caloric ; and this last in its 

 turn, during the time required to replace it in equilibrio 

 in the universe, supports the chemical activity of organic and 

 inorganic nature. Jf we can imagine all this to be possible, 

 we possess a notion how the sun can cause a body to emanate 

 from itself without loss of its own volume, and without this 

 emanated body producing on the bodies which arrest it the 

 effects of a gravitating and falling matter f." Such are two 

 entire paragraphs given without garbling, of Berzelius's theory 

 of combustion and chemical affinity, which Dr. Thomson says 

 " has a very plausible appearance, and which has been em- 

 braced either entirely or with some modifications, by several of 

 the most eminent chemists of the present day l" We should 

 like to know, what eminent chemists of the present day have 

 embraced these shapeless chimeras of Berzelius. Wherever 

 his notions of chemical affinity are intelligible, they are borrowed 

 from the Bakerian Lecture, 



Doctor Thomson's ten pages on electricity are also re-printed 

 without alteration, though he surely might have taken the 

 trouble when he plunged so deeply into magnetism Avith Mr. 

 Barlow, to have said something about the newly-discovered re- 

 lations of that power and the electric. After giving a dull de- 

 tail of ordinary electrical phenomena, he enters on galvanism, 

 or electro-chemistry, to which he devotes rather less than five 

 pages. These, indeed, contain so little matter, either interesting 

 or true, that he might have omitted the subject altogether, 

 without loss to his readers. He has repeated the gross blunder, 



• Nk/toUon'i Journal, March 1813, p. 150'. t Jl>uL ['■ Ioj- 



X System, vpi. I. ji. Kil. 



