158 Cincinnati Society of Natural History. 



Foremost in the development of experimental geology 

 stands James Hall, a pupil of Hutton, who, early in the 

 present century, formed carbonate of lime in a closed tube, 

 by pure igneous fusion, from the dissociated vapor of its ele- 

 ments. Through this result and the description of artificial 

 accidental syntheses given by Haussman, Mitscherlich and 

 others, Berthier was led, in 1823, to form minerals by mixing 

 their elements in chemical proportion. St. Claire Deville, 

 Caron, Debray and other students advanced the work by addi- 

 tion of fluxes and mineralizers. Manross employed the means 

 of double igneous decomposition with success. Ebelman 

 achieved success by aid of igneous evaporation and dissolu- 

 tion by boric acid. Gaj' Lussac, Durocher, used gaseous in 

 place of liquid means. Senarmont and Friedel made the 

 great successful innovation of introducing the action of water 

 under very high temperatures. Then came the work of 

 Daubree, which was epoch-making. He obtained very high 

 temperatures, and what were up to this time unattainable 

 pressures. 



The cause of the long delay in the progress of mineral 

 synthesis was the idea so firmly fixed in the minds of the old 

 chemists, that nature worked by mysterious means, and had 

 at her disposal indefinite time, enormous masses, and sup- 

 posed forces out of all proportion to those used in the labora- 

 tory. Then, how was it possible in a crucible, with certain 

 number of grammes of matter, to reproduce a crystal of same 

 kind, and association, as those which the volcano ejected, a 

 crucible million times larger and under enormous pressure 

 and temperature? The answer seemed too clear to admit any 

 such vain attempt. The underlying law of proportion was 

 unseen, but it only needed mure careful observers to dis- 

 cover it. 



With the crude means and limited experience at hand, pro- 

 gress was very slow down to the middle of the present cen- 

 tury. At the beginning of the cycle, there existed the two 

 opposing geological camps — the one attributing everything 

 to fire, the other all to water. After long years of bitter dis- 

 cussion, the union was accomplished through the efforts of 

 Lyell and his followers; at the same time the accunuilating 

 observations overthrew another old idea, and proved that a 



