343 



FOEEIGIT COEEESPO^N^DEKCS. 

 By Db. T. L. Peipson, of Paeis. 



Novel Production of ArUvricI C- and Anthracite (continued) — 

 Met amor pliisni — Aj-tion uf Lar-- au.d Trai^-roclcs on Calcareous 

 Strata — Production of Minercds hy Meiamorjjldc Action — Meta- 

 morpTiomd Gypsum — Reddiot Lava tico years af '^ a lialf (jbl — 

 Cotunnite and Kerasine — Origin of Crystcdlized Sulphar in Sicidy 

 — Formation of Prcdries — Their Relation to Pecd-ljorjs. 

 M. Cagniard do la Toiir formerly submitted woody matter iu closed 

 vessels to the action of great heat, with a view of obtaining coal ; but 

 his experiments, like those of Hatton, failed — the only result was 

 bitumen. M. Barouilier, repeating the experiments of Hutton and 

 Cagniard de la Tour, introduced three important modifications, which 

 have contributed to the success of the operation. Pirstly, he interposes 

 a stratum of woody matter between Ia3^er3 of clay ; in the next place, 

 the vessel is not completely closed, but so arranged that the steam, and 

 disengaged carburets of hydrogen, remain a certain time in contact with 

 the mixture of ligneous matter and clay ; and, finall}^, the temperature 

 to which his apparatus was submitted never exceeded 300 degrees (Cen- 

 tigrade). The consequence was, that the products obtained resembled 

 coal in every respect ; and, as we said before, their appearance varies 

 according to the nature of the wood employed in the experiment. They 

 vary, also, a little with the temperature. 



In a former paper we alluded to some very ingenious experiments 

 made by M. Daubree, the eminent geologist of the Paculty of Sciences 

 at Strasburg,^" by which he produced, artificially, a number of v/ell- 

 known minerals, by the sole action of water at a high temperature, sus- 

 tained for long periods of time. In a Alemoir lately published,! the 

 same author states that, by submitting pieces of pine-wood to this re- 

 markable action of hot water or steam, in a closed tube, he has obtained 

 Antliraciie. This is another new and curious fact to be added to his 

 former interesting discoveries concerning the origin of minerals. 



In a previous article:|: we have alluded, to some interesting 

 observations of ^'1. Delesse on the nietamorphism of rocks, and have 

 * See the Geologist for Feb., 1858. 



t Sur le Metamorphisme, .^-c, par M. Danbree. Paris, Victor Dalmcnt, 1858. 

 :j: The Geologist for March, 18.58. 



