LIFE, CARBONS OUTSTANDING PROPERTY 50 



contain any of the other elements, carbon excluded. This 

 relation is certainly not the result of a preference given to 

 the study of the carbon compounds but the expression of an 

 outstanding chemical property possessed by carbon itself. 

 If we fully understand this property, its causes and char- 

 acteristics, we have made a step forward in the solution of 

 the great problem of life. 



The carbon compounds are collectively designated as 

 organic compounds. This term was originated more than 

 a century ago, at which time all these compounds were ob- 

 tainable only by extraction from the plant or animal body. 

 It has been known long since that carbon compounds can 

 be made artificially. Since that time their number has been 

 increased to the enormous extent described above. It 

 must also be emphasized that all the artificially made com- 

 pounds of carbon are obtained by methods which have 

 nothing in common with nature's own ways of making such 

 substances. 



Let us review the most important high lights of our 

 knowledge concerning the carbon compounds. Most of 

 them contain, other than carbon, only the chemical ele- 

 ments, oxygen, hydrogen, and nitrogen. Some also contain 

 chlorine, bromine, iodine, sulfur, and phosphorus. Metals 

 very rarely share in these compounds. 



The most general experience is that the percentage com- 

 position of a carbon compound is of little or no importance 

 as far as its properties are concerned, since numerous com- 

 pounds have precisely the same content of carbon, hydro- 

 gen, oxygen and nitrogen, yet one of them may be liquid, 

 the other solid ; one may have a pungent odor, the other no 

 odor at all; one may exhibit a brilliant color, the other no 

 color. Many other variations may occur, although the 

 actual amounts of carbon, hydrogen, oxygen, and nitrogen 

 are the same in each compound. The conclusion is that 

 the atoms in the molecules are laid together like bricks in a 



