440 MODERN CHEMISTRY. 



far beyond any calculation of this nature. Commanding new 

 resources of experiment, and possessed of the true laws of 

 chemical combination, he pursues the various forms of matter, 

 whether simple or compound, throughout all their relations 

 and affinities ; obtaining in his progress, and as a result of 

 these affinities, numerous substances wholly unknown before, 

 yet possessing qualities as singular and strongly marked as 

 those which Nature herself proffers to our enquiry. 



Examples of these remarkable products of synthetical 

 chemistry might be endlessly multiplied. In mentioning 

 iodine and bromine we noticed the numerous and complex 

 combinations they have been made to assume ; all of great 

 interest from the relation of these two bodies to other unde- 

 composed elements around us. When speaking of Organic 

 Chemistry., we shall have to notice the production artificially 

 of certain organic compounds, not to be distinguished from 

 their prototypes in nature, and forming in this respect a dis- 

 covery which may well rank among the most eminent in 

 physical science. Of other instances we shall take only a 

 few, for mere illustration. Every new metal discovered 

 (and the activity of modern research has more than trebled 

 the number known to antiquity) has been followed through 

 a long series of combinations with other chemical elements, 

 all determined by the law of definite proportions ; yet, while 

 obedient to this great common law, yielding numerous pro- 

 ducts altogether new to us and to the natural world. Some 

 of these are of eminent utility to man ; others possess pro- 

 perties of strange and fearful kind ; such as those explo- 

 sive metallic and gaseous compounds, of which the parts 

 seem to be compelled into an unstable union, prone at any 

 instant to sudden and violent dissolution. Ghmpowder 

 that extraordinary substitute of chemical force for manual or 

 mechanical means of destruction cannot historically be 

 called an invention of Chemistry, though expressing curious 



