306 GENERAL PHYSIOLOGY 



living proteid is explained as the result of the absorption of 

 oxygen ; for. since the atoms of cyanogen are in active vibration, 

 the carbon-atom of the cyanogen at the approach of two oxygen- 

 atoms will pass out of the sphere of influence of the nitrogen- 

 atom into that of the oxygen, and will unite with the latter into 

 carbonic acid. Thus the cause of the formation of carbonic acid, 

 i.e., of the decomposition of living substance, lies in the cyanogen, 

 and the condition is the intramolecular introduction of oxygen. 



The idea that it is the cyanogen especially that confers upon 

 the living proteid molecule its characteristic properties is 

 supported especially by many analogies that exist between living 

 proteid and the compounds of cyanogen. In the first place, a 

 product of the oxidation of cyanogen, cyanic acid, HCNO, 

 possesses great similarity to living proteid. Pfliiger calls 

 attention to the following interesting points of comparison. Both 

 bodies grow by polymerisation, by chemically combining similar 

 molecules like chains into masses ; the growth of living substance 

 takes place thus, and in this way also the polymeric cyamelid, 

 H w C n N ?l O n , comes from cyanic acid, HCNO. Further, both 

 bodies in the presence of water are spontaneously decomposed into 

 carbonic acid and ammonia. Both afford urea by dissociation, 

 i.e., by intramolecular rearrangement, not by direct oxidation. 

 Finally, both are liquid and transparent at low temperatures, and 

 coagulate at higher ones, cyanic acid earlier, living proteid later. 

 " This similarity," says Pfliiger, " is so great that I might term 

 cyanic acid a half-living molecule." 



These points of view yield most important suggestions con- 

 cerning the question how life may have arisen upon the earth. 

 " When we think of the beginning of organic life, we must not 

 think primarily of carbonic acid and ammonia ; for they are the 

 end of life, not the beginning." " The beginning lies rather in 

 cyanogen." 



Hence the problem of the origin of living substance culminates 

 in the question: How does cyanogen arise? Here, organic 

 chemistry presents the highly significant fact, that cyanogen and 

 its compounds, such as potassium cyanide, ammonium cyanide, 

 hydrocyanic acid, cyanic acid, etc., arise only in an incandescent 

 heat, e.g., when the necessary nitrogenous compounds are 

 brought in contact with burning coal, or when the mass 

 is heated to a white heat. " Accordingly, nothing is clearer 

 than the possibility of the formation of cyanogen-compounds 

 when the earth was wholly or partially in a fiery or heated state." 

 Moreover, chemistry shows how the other essential constituents of 

 proteid, such as the hydrocarbons, the alcohol radicals, etc., can 

 likewise arise synthetically in heat. 



" It is seen how strongly and remarkably all facts of chemistry 

 point to fire as the force that has produced by synthesis the 



