66 



THE SYNTHESIS OF CARBOHYDRATES 



Such a peroxidic compound (III.) as is postulated above should 

 be capable of losing oxygen either in one or in two stages with 

 regeneration of unaltered chlorophyll and formation of for- 

 maldehyde (IV.) 



R 



ON 



>Mg.O.Qj< 



1>NH 



m 



R 



1>NH 



Mg.O.Cfr. 



,0 



f >N 



R 



\ 



1>NH 



Mg°<H ^ R i 



r>N 



1>N 



Mg+0+HCHO 



IV 



Within the living cell the decomposition of the peroxide 

 formaldehyde compound (III.) is assumed to be brought about 

 by an enzyme, the existence of which enzyme is supported by 

 the experimental evidence relating to the assimilation number 

 which has already been considered (p. 43). 



Willstatter and Stoll's views are founded on Baeyer's 

 theory ; this formaldehyde hypothesis is certainly attractive 

 and is supported by many and various observations ; its 

 degree of probability is a matter of personal opinion, being 

 dependent on the relative values of the known facts. But 

 the attractiveness of a hypothesis, or of a witness, or of an 

 item of evidence must not outweigh the many deficiencies, 

 the fulfilment of which is requisite for a relative scientific 

 proof, an absolute proof being hardly possible ; wherefore the 

 conclusion is reached that the formaldehyde hypothesis is 

 not proven. 



OTHER OPINIONS. 



FORMIC ACID. 



Erlenmeyer was the first to suggest that formic acid is 

 the more likely intermediate product of early origin, but it is 

 only of recent years that renewed attention has been given to 

 the possibility. The work of Spoehr has already been men- 

 tioned : he demonstrated that carbon dioxide and water are 

 easily reduced to formic acid by means of radiant energy ; 



