Dr Petzholdt on the Formation of the Diamond. 325 



there is hardly any chemist who has not performed more or 

 less extensive experiments on the subject. That the results 

 of such investigations have been published by but few chemists, 

 is no proof that few experiments have been made, for human 

 nature and vanity prefer silence to publicity, where investiga- 

 tions have failed, and hopes have been disappointed. 



All the experiments to form artificial diamonds may be re- 

 ferred to two methods, viz. the attempt to fuse carbon, and the 

 endeavour to separate carbon in a crystalline state from a 

 highly carbonaceous compound, by means of decomposition. 

 It need hardly be remarked that ajl the trials have hitherto been 

 in vain. The experiments made with the first view have been 

 rendered unsuccessful by the infusibility of carbon, and the others 

 proceeding on the second idea have always resulted in the pro- 

 duction of carbon in the form of a black substance.* Lastly, 

 if any one should be of opinion that, by the assistance of a 

 constantly operating electrical stream, highly carbonaceous 

 bodies might be decomposed so slowly that carbon might be 

 separated in a crystalline condition, that is, in the form of 

 diamond, just as copper and the other metals have been re- 

 cently obtained, in a crystalline state, fi-om solutions, by Jacobi's 

 method, such an expectation will prove to be a vain one ; for, 

 on the one hand, the substances most suited to galvanic de- 

 composition are non-conductors of electricity, as, for example, 

 sulphuret of carbon, oil of turpentine, copaiva balsam, &c. ; 

 and on the other, if we should be successful in separating, 

 from any compound, crystalline carbon on the conducting wire, 

 yet, according to theory, at the very moment when even the 

 most delicate covering of crystalline carbon should be deposit- 

 ed, all further action on the decomposing liquid would be inter- 

 rupted, for the matter of diamond itself is known to be a non- 

 conductor of electricity. t 



* A pretty extensive collection of the experiments on this subject, to- 

 gether with the references, is to be found in Ersch and Gruber's AUgemdne 

 Encyclopddie tier K'dngte und Wtsseiichaftcn, under the article Diamant. See 

 also in Gmclin's Handbuch der T/tcoretischen Chcmie, vol. i. the chapter on Car- 

 bon. 



t From Petzholdt's Beitriige zxir Naturgcschichtc des Diamantcs, 1842, 

 VOL. XXXIV, NO. LXVIII. — APRIL 184'3. Y 



