38 THE NATURE AND ORIGIN OF LIFE 



this new problem ; you set up a reaction between a certain 

 quantity of the body you are studying and sulphuric acid 

 and you note what happens. This is what the old chem- 

 istry did ; you will find in the books of twenty years ago a 

 description of each body, first of its distinctive characters, 

 and then of its reactions with a certain number of chemical 

 agents chosen beforehand. 



Advances in atomic chemistry enable us to condense in 

 few words or in stereochemical formulae, whatever it is 

 possible to foresee with regard to the reactions of one body 

 with all other possible bodies. Now that this new kind of 

 work has been accomplished, we say that the body has been 

 analysed into its junctions. The excellence of the method 

 is this such an analysis is not made from the point of view 

 of the reactions of the body studied in connexion with a 

 single body chosen beforehand, but with a view to all 

 other chemical bodies whatever. 



For example, in this new language, we say that glycerine 

 is a triatomic alcohol having the primary alcohol function 

 twice and the secondary alcohol function once. This 

 enables a chemist to foresee its reactions with a host of other 

 bodies ; but clearly it will be more convenient for a druggist 

 to know that it is a syrupy liquid, colourless, with a certain 

 taste and other qualities easily recognized. 



Analysis into junctions after this fashion is of priceless 

 value to us in the study of life. 



Analysis of Bodies by Means of our Sense Organs 

 Among the properties by which the chemists of other 

 days recognized certain definite bodies, there stood apart 

 as being easily used the organoleptic properties, that is, 

 properties recognized by the direct use of our sense 

 organs. Taste, colour, smell are in the front rank of these 



