432 MODERN CHEMISTRY. 



chemical philosophy, and especially on Organic Chemistry as 

 one of its great departments. 



The procedure of Chemistry, as an experimental science, 

 may be resolved exclusively into the two great methods of 

 Analysis and Synthesis ; the separation of parts before united, 

 or the union of parts before separate. No chemical opera- 

 tion can occur in which one or other of these changes is not 

 concerned ; and the attainments of the science are best esti- 

 mated by the facility and exactness with which such changes 

 are effected. Of these two methods, both depending on the 

 relative affinities of different kinds of matter, analysis has a 

 natural precedence. Even in the processes of nature the 

 separation of compounds is more obvious than the reunion of 

 parts. The changes and combinations upon which organic 

 existence depends forming the chemistry of animal and 

 vegetable life are slow and occult processes compared with 

 those which dissever such combinations, and restore the parts 

 to more elementary state. And when the subject assumed 

 the character of an experimental science, the chemist found 

 himself surrounded by innumerable compound bodies, readily 

 decomposed, and suggesting that more formal analysis which 

 might collect the parts, determine their nature, and fix the 

 proportions in which they severally exist. 



The method of synthesis comes in natural sequence to 

 this ; affording a test of the truth of analytical results, and 

 satisfying a rational curiosity as to the effects of new combi- 

 nations among the innumerable forms of matter around us. 

 In both these operations however, and as a first principle of 

 all chemistry, it is to be kept in mind that no matter is 

 either created or lost, whatever the changes or combinations 

 taking place.* In clearly fixing this principle, which was 



* Plutarch ascribes to Empedocles a passage which is well descriptive of this 

 great principle of Chemistry : 



pvffis ovdtvos f(rr\v 

 IS re 



