CHEMICAL SCIENCE. 237 



washing, by the aid of boiling nitric acid, until the last traces are removed. 

 Silliman's Journal. 



ON THE ARTIFICIAL PRODUCTION OF THE DIAMOND. 



During the year 1853, M. Despretz announced to the French Academy 

 that he had succeeded, by long- continued voltaic action, in depositing crys- 

 tallized carbon, having all the properties of the diamond.* These conclu- 

 sions, so extraordinary, have induced Despretz to review the whole subject, 

 in a communication recently presented to the French Academy. The 

 facts seem indisputably to be, that carbon was deposited at one of the 

 terminal poles of the battery, in a crystallized form that of the truncated 

 octohedra; also in amorphous grains, and in transparent plates. It must be 

 borne in mind, that although the quantity of carbon so deposited was 

 sufficient for testing and experiment, yet the crystals were microscopic, the 

 entire mass having the form of a powder. The charcoal operated upon by 

 the battery was prepared from crystallized sugar candy, and was free from 

 every trace of mineral substance. The products of the deposition M. 

 Despretz submitted to Gauden, famous for his experience in the cutting 

 and polishing of gems. Gauden, after trying the powder in every possible 

 manner, gave it as his unhesitating conclusion, that no other powder than 

 that of the diamond could have cut and polished diamonds and rubies as 

 that did, " and appears to confirm, in the clearest manner, the existence on 

 the terminal battery wires of true implanted diamonds." , 



The result, therefore, of Despretz's experiments may be summed up in 

 his own words as follows : 



" Have I obtained crystals of carbon which can be isolated and weighed, 

 and of which the index of refraction and the angles of polarization may 

 be determined ? Certainly not. But I have simply produced, by the arc 

 of induction, and by weak galvanic currents, carbon crystallized in black 

 octohedra, in colorless translucent octohedra, in colorless and translucent 

 plates, the whole of which had the hardness of the powder of the diamond, 

 and which disappeared in combustion without leaving any perceptible 

 residue." 



INFLUENCE OF BISMUTH ON THE DUCTILITY OF COPPER. 



There has recently been exported from Australia a black copper in in- 

 gots, possessing some peculiar properties. Although of a high percentage, 

 the color is bronze ; it is but little ductile ; the fracture is loose and crys- 

 talline, which may be removed by refining in the ordinary methods. 



M. Levol, Assayer of the Mint at Paris, has analyzed this copper before 

 and after refining, with the following results : 



* See Annual Scientific Discovery, 1854, page 241. 



