592 SCIENCE PROGRESS 



which the compounds are obtained through the destruction of 

 the protein molecule. 1 



A great variety of syntheses of organic compounds has 

 shown that the path to synthesis was plainly indicated in the 

 methods, and stages, of analysis by which they were originally 

 isolated. In the case of protein substances this process is, 

 in foremost line, a simple hydrolysis. E. Fischer has shown 

 that two amino acids may unite to form a more complex 

 compound by simple dehydration. We may suppose that in 

 the beginning it was the same. 



These hydrations and dehydrations may or may not have 

 taken place under the active influence of sunlight. For a time, 

 under the dominance of the Helmholtz-Kelvin idea as to the 

 age of the sun, it seemed as if the beginnings of life must have 

 been in the dark, or at least in the diffused light of a nebular 

 cloud. It is evident now, as Arrhenius 2 and others have shown, 

 that these calculations had no decisive value. Insolation in 

 the Archean period of the earth may have been even more 

 intense than at the present time, or at least the chemically 

 active portion of the spectrum may have been. 



It seems highly probable that the beginnings were in the 

 absence of free oxygen, and that oxidations came into play, 

 as they do still, only at a later stage of organic complication, 3 

 and after free oxygen had been introduced into the atmosphere 

 through organic activity itself. This latter process, thanks to 

 the labours of G. Bertrand, Wilstatter and others, we are 

 probably now in a position correctly to conceive. Bertrand 4 

 showed that in the case of the oxidase laccase, the active 

 principle seems to be manganese, and that the activity of this 

 ferment is directly proportional to the amount of the metal 

 that it contains. 



Apparently the office of the metal is to seize the oxygen 

 atom at the moment of the dissociation, under the influence 

 of sunlight or by other means, of the carbon dioxide molecule, 

 and to hand this oxygen over, after a passing union, in a 

 "nascent" state. In a similar way Wilstatter 5 has shown 



1 Cf. Mann, loc. cit. ; A. E. Taylor : Univ. of Cal. Pubs., Pathol. Series, No. 9. 

 J L.c, p. 61 ; also Lehrb. d. Kos. Physik, 1904. 

 3 Gautier : Chimie de la Cellule vivante, 1898. 

 * Compt. Rend., 122. 1132, 1896 ; 124. 1032, 1897. 

 5 Liebig's Annalen, 350, 48, 1906 ; 354, 205. 



