THE TECHNOLOGIST. [Oct. 1, 1864. 



124 CHEMISTRY. 



Chemistry, in its theoretical signification, is that science which 

 teaches us the internal properties of bodies and the mutual action of 

 their elements. Its grand practical division is into — 1. Inorganic of 

 mineral chemistry ; 2. The chemistry of organised bodies, which we so 

 term because, though now dead, they have had their origin in a vital 

 principle ; and 3. Organic chemistry, comprehending those substances 

 which have a present vital existence. 



Analytical chemistry devises methods for detecting the various 

 elements of a compound, and estimating their proportions. Synthetic 

 chemistry enables us to form homogeneous compounds of dissimilar 

 substances, and is used to verify the results of analysis. Arraying or 

 docimacy is the dry method of analysis. 



Practical or applied chemistry comprises the application of chemical 

 principles to the arts : for example, to the making and fixing of colours 

 for paints and dyes ; to the processes of tanning, distilling, and brewing ; 

 to the manufacture of glass, porcelain, and artificial stones ; and to 

 domestic and culinary purposes. It is more elegantly termed techno- 

 logical chemistry, and to this branch belongs also metallurgy, or the art 

 of separating metals from their ores. 



Pharmaceutical chemistry relates to the preparation of remedies 

 employed in medicine. 



Medical chemistry is allied to physiology, and treats of the 

 application of chemical principles in the theory and practice of 

 medicine. 



Toxicological chemistry refers to poisons, their special action upon 

 the system, and the means of detecting them. 



The subdivisions of the science are still increasing, and the varied 

 uses to which it is now applied are so great, that even subordinate 

 branches are growing or taking place out of those that had previously 

 existed. 



It was said of Mercury, in the days of mythology, that he plundered 

 Neptune of his trident, Venus of her girdle, Mars of his sword, Vulcan 

 of his implements, and Jupiter of his sceptre. This is but an allegory 

 referring to Chemistry, of which Mercury was the patron, and through 

 the means of which he collected so much knowledge from unseen as 

 well as visible sources ; and now, Justice, acting upon her principle of 

 retribution as to matters of this world, makes him return, with interest, 

 lo us, the prizes pillaged from the elements and the gods. 



No one can tell to what extent the investigations in Chemistry may 

 go ; — no one can define its limit. It enabled Daguerre to seize the 

 fleeting shadows of the air and fix them immutable upon metal ; and 

 hereafter its discoveries may transfix the very sounds of human voices, 

 and hold them quivering in the hand as echoes to the wind. Even 

 thought itself may be reached, and the very breath that gives it silent 

 aspiration be made to stand out upon tablets like recorded words of 

 utterance. 



