CHEMICAL SCIENCE. 219 



If it be maintained that graphite is an organic product, it must be 

 admitted that in the case of newly-fallen meteorites it can proceed 

 only from organic matters belonging to another world than our own. 



In his report on Alibert graphite, M. Dumas presents some consid- 

 erations on the probable origin of graphite and of the diamond. M. 

 Pespretz and others ascribe to lire the change of carbon into diamond ; 

 Newton ascribed it to the coagulation of a fatty or oily body ; Liebig 

 says the diamond is slowly formed by processes which determine the 

 prolonged putrefaction of a liquid body rich in carbon and in water; 

 then, contrary to M. Despretz's method a high temperature would be 

 unfavorable to a successful attempt. Adopting Newton's hypothesis, 

 M. Gocppert states, in "a memoir on the solid bodies entering into 

 llie composition of the diamond, and considered with regard to their 

 organic or inorganic origin," that he is disposed to class the diamond 

 among the products of the decomposition of organic matters. All 

 these hypotheses M. Dumas rejects ; according to him the diamond 

 is crystallized carbon, at the moment of its production and in the 

 midst of a mass which has been exposed merely to the heat necessary 

 to soften it, provided this condition is sufficiently prolonged. 



Finally, M. Dumas frankly admits that nothing positive is known 

 as to the true origin of the diamond, though the substance most 

 allied to it, silicum, is perfectly known, and very beautiful specimens 

 of it are obtained. 



However, it is positively ascertained that the diamond and graphite 

 have not the same origin, and that the residue of every carboniferous 

 substance, treated at a high temperature, proves to be but a variety of 

 graphite. The new carbon found by M. Alibert in the i^ines of 

 Marinski, situated at the summit of Batougol, on the Siberian fron- 

 tiers, is then a graphitoid carbon of the most beautiful kind, formed 

 by volcanic phenomena. M. Jaquelain, after carefully comparing the 

 external characteristics of Alibert graphite with that obtained by his 

 process, concludes that the conditions under which they are produced 

 must be analogous. 



In fact, on comparing the texture of the two carbons, they will be 

 found sometimes of a metallic, mirror-like lustre ; at another time the 

 surface will be of shining steel-gray, mammillated as if it had been 

 half fused, and had passed through a pasty stage. This appearance is 

 similar to that of oxyd of iron, nodulous, brilliant, with mammillated 

 surface, known by the name of brown hematite. M. Jaquelain is in- 

 clined to admit that tarry and pyrogenated products, transformed in 

 immense proportions into carbon and hydrogen, under the influence 

 of igneous rocks, become accumulated in rents and excavations, 

 causing an aggregation of carbon, and inducing a fusion analogous to 

 that of carbon in retorts for lighting gas and of graphitoid carbon 

 destined to form the pencils used for the electric light. 



On this point, M. Jaquelain narrates one of his own recent exper- 

 iments. On decomposing some sulphide of carbon in a porcelain 

 tube in presence of pure copper, heated to about 3,008, sulphite of 

 copper and graphite were formed, externally similar to natural graph- 

 ite. Lond. Chem. News, from Cosmos. 



