526 Mr. T. S. Hunt on the Theory of Chemical Changes^ 



mankind ? Thus, in the case of the point of maximum density in 

 water, man has traced the wise design, the benevolent provision 

 of the Almighty, by which our seas, lakes, and rivers are avail- 

 able for human purposes, and not converted into solid frozen 

 masses. He has wondered, but as yet his wonder has resulted 

 in no discovery for the benefit of his species. 



In France, indeed, philosophers have adopted this point as a 

 natural unit of density. It has thus supplied us with a particular 

 standard ; but how little is^ this in comparison with the advan- 

 tages which ought to result from a due application of this sur- 

 prising phaenomenon ! Again we repeat our inquiry, How comes 

 it that this second class of physical singularities has contributed 

 little or nothing for the practical good of mankind ? 



The answer plainly is, because we are unacquainted with the 

 general laws of which they are the consequences. How is it 

 that in optics we can employ so extensively and so usefully the 

 position of minimum deviation ? Evidently because we are 

 acquainted with the general laws upon which its existence 

 depends. 



In order, then, to be enabled to employ with advantage the 

 singularities of nature, we must acquaint ourselves with the 

 general laws of which they are the consequences. The principal 

 of those which have not been yet so employed appear to depend 

 upon the molecular constitution of bodies. Another reason is 

 thus perhaps added to the many which combine to render mole- 

 cular physics one of the most interesting subjects of the present 

 day. Experimental research has done much, the difficulties 

 which encompassed its mathematical treatment are fast disappear- 

 ing, and its claims upon consideration seem fairly appreciated. 



LXXXII. Considerations on the Theory of Chemical Changes, and 

 on Equivalent Volumes. By T. S. Hunt, of the Geological 

 Commission of Canada^. 



IN the proposed inquiry we commence by distinguishing be- 

 tween the phsenomena which belong to the domain of physics, 

 and those which make up the chemical history of matter. We 

 conceive of matter as influenced by two forces, one of which 

 produces condensation, attraction, and unity, and the other, 

 expansion, repulsion, and plurality. Weight, as the result of 

 attraction, is a universal property of matter. Besides this, we 

 have its various conditions of consistence, shape, and volume, 

 with the relation of the latter to weight, constituting specific 



♦ From the American Journal of Science and Arts, 2nd series, vol. xv. — 

 March, 1853. 



