262 BOGERT— CARBON COMPOUNDS. [April 20. 



methane, CH^. These proving insufficient, multiple and mixed types 

 were invented. 



So early as 1838, Gerhardt had called attention to the fact that 

 by the action of sulfuric acid upon various substances compounds were 

 produced in which the characteristic properties of the constituents 

 were not present. To distinguish such, he coined the term " copu- 

 lated compounds." His original views were considerably enlarged 

 and modified by Berzelius. According to this point of view, many 

 radicals were assumed to be composed of several simpler ones. 

 Thus, the fact that many monobasic acids (written on the water 

 type) could frequently be decomposed with liberation of the CO 

 group as COo, together with the alcohol radical, caused the acid 

 radicals to be looked upon as made up of CO and an alcohol radical, 

 CHg-CO — O — H, instead of C2H3O — O — H, and paved the way 

 for the modern structural formulas. 



It was Williamson who showed that the existence of compound 

 radicals could be assumed just as well for inorganic as for organic 

 compounds, and that organic chemistry could no longer be correctly 

 designated as " the chemistry of the compound radicals." 



With the discovery of substances common to both plants and 

 animals, the subdivision of organic chemistry into vegetable and 

 animal chemistry was quite generally abandoned. 



Gmelin says in his "Handbook" (Vol. VH., pp. 4 and 5) : 



" Carbon is the only element which is essential to organic compounds ; 

 every one of the other elements may be absent from particular compounds, 

 but no compound which in all its relations deserves the name " organic " is 

 destitute of carbon. ... If we were to regard as organic those carbon com- 

 pounds which have been classed hitherto among inorganic substances, namely 

 carbonic oxide, carbonic acid, sulfide of carbon, phosgene, cast iron, etc., we 

 might define organic compounds simply as ' the compounds of carbon ' ; but 

 organic compounds are still further distinguished by containing more than one 

 atom of carbon. . . . Hence the term ' organic compounds ' includes all 

 primary compounds containing more than one atom of carbon." 



This last qualification was unfortunate, for it was soon shown that 

 the atomic weight of carbon was 12, instead of 6, and that, therefore, 

 methyl alcohol and formic acid contained only one atom of carbon 

 and would be excluded from organic compounds by the above 

 definition. 



