EXPERIMENTS WITH RADIUM 95 



suitable media set up catalytic actions, and thus 

 act as a means of synthesising complex organic 

 compounds : a method not hitherto employed. It 

 was for this reason that bouillon, of the composition 

 used in the experiments with radium, was used, 

 since it contained all the constituents of protoplasm, 

 and it seemed at the time quite possible, not to 

 say probable, that the physical properties of the 

 cyanogen molecule, as well as its chemical proper- 

 ties, justified the very shrewd conception of Pfliiger, 

 that the molecule of cyanogen is a semi-living thing. 

 The fundamental difference between living pro- 

 teid as it constitutes living substance, and dead 

 proteid as it occurs in egg albumen, is in the self- 

 decomposition of the former and the stable con- 

 stitution of the latter. 



As Verworn ^ remarks : — " The starting point for 

 further consideration is afforded by the fact that 

 of the heterogeneous decomposition products of 

 living proteid, such as uric acid, creatin, and, more- 

 over, the nuclein bases, guanin, anthin, hypoxanthin, 

 and adenin, a part contains cyanogen as a radical, 

 and a part like urea, the most important of all 

 the decomposition products of living proteid, can 

 be produced artificially from cyanogen compounds 

 by a rearrangement of the atoms. This points 

 strongly," he thinks, " to the probability that living 

 proteid contains the radical cyanogen, and thus 

 differs fundamentally from dead or food proteid." 

 Thus, according to Pfluger, "in the formation of 

 1 hoc. cit. p. 306. 



