A PPENDIX 



SOME ELEMENTAEY FACTS OF OEGANIC CHEMISTRY 



THE following elementary facts may help the student who has neglected 

 the study of the outlines of Organic Chemistry in understanding the 

 chemical problems of physiology. 



Organic compounds are built round the four-handed carbon atom 



When each hand links to the one-handed hydrogen atom, 

 METHANE H 



H C H is formed. 

 H 



By taking away a hydrogen atom from two Methane molecules and 

 linking these molecules together 



ETHANE H H 



I I 

 H C C H is produced. 



H H 



By further linking more and more of these molecules together, similar 

 molecules containing three, four, five or more carbon atoms are produced. 



When each carbon has its due proportion of hydrogen atoms it is 

 saturated, but if two hydrogen atoms are let go, the unoccupied hands 

 of the carbon may join and form an unsaturated molecule, thus : 



Ethane becomes Ethylene H H 



H C=C H 



When one hydrogen atom is taken away and the molecule has a hand 

 ready to link with some other substance a radical is constituted, and 

 these are known as METHYL, ETHYL, etc. 



