( 163 ) 



That the choice fell on this reaction was due to this that it has 

 appeared from the investigations of Boudouard 1 ) and others that 

 when CO is converted into CO, and C, the carbon is deposited in 

 the form of graphite, so that it was to be expected that when we 

 start from the righthand system, and lead CO s over diamond at 

 constantly increasing temperature, graphite, which will be immediately 

 visible even in exceedingly small quantities will deposit on the 

 diamond, the reaction proceeding simultaneously from left to right. 



[It is hardly necessary to observe here that we discuss the reaction 

 in the gas phase, in which the gaseous carbon is one of the reading 

 components. 



The circumstance that the system is heterogeneous, and according 

 to the molecular theoretical views by the side of the homogeneous 

 reaction two more heterogeneous transformations take place, viz. : 



diamond — *• C m pow and C oap our — * graphite, between which the 

 homogeneous reaction forms the link, made us suppose, we had 

 found in this example a means to test our dynamic conception con- 

 cerning a chemical reaction] "). 



It is self-evident that if the experiment is to prove anything, care 

 must be taken that the temperature never falls, because in this case 

 the depositing of graphite might be ascribed to a shifting of the 

 equilibrium from left to right. 



To be sure that this was out of the question it was desirable to 

 make the temperature constantly increase during the experiment. 



Before proceeding to the experiment we gladly avail ourselves of 

 this opportunity to mention that the diamond powder with which 

 the above mentioned investigation was made, had been kindly sup- 

 plied to us by Messrs. Asscher, to whom we here express our great 

 indebtedness. 



As it was important for our investigation to start from white 

 diamond powder, the diamond received by us, which had a grey 

 colour in consequence of impurities, was heated in an open china 

 mug, by means of which a perfectly white powder was obtained. 



Before now proceeding to the decisive experiment, it was necessary 

 to investigate first of all whether at the temperature at which we 

 intended to perform our investigation, diamond is already converted 

 to graphite. 



For this purpose the white diamond powder was heated for an 



i) Ann. Ghim. Phys. (7) 24, 5-85 (1901). 



2 ) The passage between [ ] is added in the English translation. 



11* 



