ORGANIC CHEMISTRY. 291 



stances Lave been made in the chemist's laboratory which 

 were formerly regarded as solely the products of the agency 

 of life, and consequently the theory of a special vital force 

 governing the attractions of matter in plants and animals 

 has been gradually abandoned. Urea (a constituent of 

 urine), alcohol, acetic acid, alizarine (a beautiful dye-stuff), 

 and indigo, are some of these organic bodies which have 

 been synthetically prepared that is, by a putting together 

 of so-called inorganic materials. 



The branch of chemistry you have been studying is some- 

 times called Inorganic, because opposed to Organic Chem- 

 istry; another and very suitable name is Mineral Chem- 

 istry, since it concerns chiefly mineral substances. This 

 division into Mineral and Organic Chemistry is, however, 

 a mere matter of convenience, and not countenanced by 

 Nature. The same elements compose the bodies and sub- 

 stances existing in the three kingdoms mineral, vegetable, 

 and animal; and the same laws of attraction hold these 

 elements together, and govern their combinations. 



Certain organic substances do, indeed, differ radically in 

 their nature and formation from mineral bodies, exhibiting 



O 



a fibrous and cellular structure, and forming parts of organs 

 peculiarly the product of life ; these are termed organized 

 bodies, and must not be confounded with organic bodies. 

 As an example of this difference take the case of a fruit ; 

 the fibrous, cellular, pulpy matter forming the woody frame- 

 work of the fruit is an organized body ; but the acids, the 

 sugar, the gum, the starch, the coloring matter, etc., con- 

 tained in these living organs are organic bodies. Whether 

 the chemist will ever be able to imitate organized struct- 

 ure is exceedingly problematical. The distinguishing pow- 

 er between organic and organized bodies lies in the micro- 

 scope. 



407. Constituents of Organic Substances. "We have stated 



