430 MODEKN CHEMISTRY. 



In truth, it can hardly be defined or described so as not to 

 include its great purposes and powers; and, together with 

 these, that exactness of methods upon which its progress 

 mainly depends. 



All great truths, whether of morals or physics, are marked 

 by their simplicity. Although not an absolute test, since 

 false principles or paradox often seek shelter under the 

 same forms, yet we may affirm that in proportion as truths 

 become more complete and comprehensive, so are the ex- 

 pressions appropriate to them more simple and determinate. 

 And this is especially the case in regard to physical know- 

 ledge. Though facts have multiplied, so as to encumber the 

 mind of the student, and seemingly to dissever the material 

 world into endless fractional parts, yet has the discovery of 

 new relations and connections tended unceasingly to reduce 

 these facts under more general laws, and to give to science a 

 simplicity of higher kind at every great step in its progress. 

 To what future point this process of integration may proceed, 

 we hardly venture to surmise. We may, however, express 

 our belief that we stand but on the margin of what will be 

 hereafter attained. 



We have already said that Chemistry, from its nature and 

 objects, forms of necessity a principal basis of such progress. 

 And this brings us at once to the definition of these objects 

 a definition which, simple as we may seek to render it, 

 must yet be made to include actions infinite in number and 

 variety different throughout all forms of matter minis- 

 tering directly or indirectly to all the phenomena of the 

 natural world and essential to the being and maintenance 

 of every form of animal and vegetable life. Chemistry can 

 only be described by a generalisation which will embrace all 

 these conditions within itself. 



Matter is presented to us in the universe at large, as 

 masses acting upon each other in obedience to the law of 



