243 
rOllEIGN CORllESrONDENCE. 
El' De. T. L. PHirsoN, OF Paeis. 
Novel Prodticiiuii of ArfificiuJ Cutd (iiul Anf/iracite (cnntiiiui'd) — 
Mctaniorphism — Action of Lara, 'iikJ Tr(q)-rucJ,-s on Calcareous 
Strata — Production of Minerals by Meta)norjjhic Action — Mela- 
morpltoml Gypsum — Red-hot Lara two years and a half old — 
Cdluunife and Kerasine — Oriyin of Crystallized Sulphur in Sicily 
— Foriuatiou of Prairies — Their Relation to Peat-hoys. 
M. Cagniard de la Tour formerly submitted woody matter in closed 
vessels to the action of great heat, with a view of obtaining coal ; but 
his experiments, like those of Uutton, failed — the only result was 
bitumen, M. Barouilicr, repeating the experiments of Hutton and 
Cagniard de la Tour, introduced three important modifications, which 
have contributed to the success of the operation. Firstly, he interposes 
a stratum of woody matter between layers of claj^ ; 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, finally, 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 Faculty of Sciences 
at Strasburg,""-' by which he produced, artificially, a number of well- 
known minerals, by the sole action of water at a high temperature, sus- 
tained for long periods of time. In a Memoir 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 
Anthracite. This is another new and curious fact to be added to his 
former interesting discoveries concerning the origin of minerals. 
In a previous article;!: --wo have alluded to .sonic interesting 
observations of JNI. Dulesse on the nietaniurphism of rocks, and have 
* See the Geologist for Feb., 1858. 
t Sur k Mdamorphisnie, S^-c, par M. Daubree. ParU, Victor Dalmoni, 1858. 
% The Geologist for March, 1858. 
