424 THE BEGINNINGS OF LIFE. 



plex body known as pyrogallic acid. Here, all the 

 products are still mere ordinary chemical compounds. 

 But in those processes which are most familiarly 

 known as fermentations, some of the higher products 

 constitute what we know as c living ' matter, and 

 soon separate from the solution in the form of visible 

 specks or particles 1 . This is what occurs in the 

 vinous, and all those more or less putrid fermenta- 

 tions of animal and vegetable substances with which 

 living matter is invariably and necessarily associated. 

 These are all of them exceedingly complex processes 2 , 

 which are as yet very imperfectly understood, The 

 results of the experiments of many investigators, how- 

 ever, compel us to believe that living matter is one 

 of the products, in these fermentations. 



Double simultaneous changes of a synthetic and 

 analytic character are familiar enough to chemists. 

 When olefiant gas (C 2 H 4 ), or the vapour of alcohol or 

 ether, is passed through red hot tubes, a complex body 

 known as naphthalene (C 10 H 8 ) is obtained in addition 

 to such lower products as marsh gas (C H 4 ), carbon 

 and hydrogen. Several acids when heated yield water 

 and a di-acid : thus tartaric acid yields di-tartaric 

 acid, whilst glycol yields di-glycol, and . even tri- and 

 tetra-glycol. More notable, however, than the oc- 



1 See pp. 77-79. 



2 Even in the vinous fermentation there are, as Pasteur has shown, 

 non-volatile products, in addition to such derivatives as succinic acid, 

 glycerine, alcohol, and carbonic acid. 



