322 Dr Petzholdt on the Fonnation of the Diamond. 



contemporaneously (in a geological sense) with the diamond ; 

 yet this circumstance by no means tends to support the idea 

 of any sort of connection between their formation and that of 

 the diamond, because the recent formation of these bodies can 

 be observed every where, and where no diamonds are to be 

 met with. The association of all these substances, which we 

 have termed accidental, is merely caused by the geognostical 

 constitution of the district through which the river-course of 

 the present day extends, by the nature of that course itself, 

 by specific gravity, and by many other circumstances having 

 not the smallest concern with the formation of the diamond. 

 The strongest proof, however, of the recent origin of the dia- 

 mond, is its occurrence in the loose rolled matter in which 

 and with which it was formed, combined with the want of suc- 

 cess that has hitherto attended the search for the diamond 

 embedded in those rocks, regarding which it is so easy, on the 

 other hand, to prove that from them all the other rolled bodies 

 had their origin. We leave entirely aside the question, whe- 

 ther the prevalent popular belief in the East Indies and Brazil, 

 that diamonds ai-e still produced,* be an instinctive percep- 

 tion of the truth, or a deceptive notion. 



Further, the diamond must have been formed in the moist 

 way from a liquid, because otherwise it would have presented 

 none of the included splinters of quartz of which I have 

 spoken in another place,t and of which some even exhibit 

 the vegetable cellular texture. 



Lastly, from all that we know, the material from which the 

 diamond was formed, by the separation of crystalline carbon, 

 could only have been a substance rich in carbon and hydrogen, 

 such as, owing to the requisite chemical properties, can only 

 be looked for in the vegetable kingdom ; and we are forced to 

 consider the diamond as produced from this substance, con- 

 sisting of carbon and hydrogen, by means of decomposition. 

 The determination of the nature of this process is solely a 

 chemical matter ; and Liebig, who has undeniably rendered 

 the greatest service to our knowledge of the decomposition of 



* See Leonliard's ropuldre Vorlesungcn iibcr Gcologie, vol. iii. p. 497. 

 t Vklc Jameson's Journal for January 184S, p. 187. 



