74 Intelligoice and Miscellaneous Articles. 



was insufficient to maintain the temperature of ebullition in that so- 

 lution. And this is just what we might have expected to find, on 

 account of the following circumstances. The heat, as the geological 

 associations and history of the new-red-sandstone would appear to 

 show, could have been but partially applied ; the quantity of earthy 

 matter mingled with the solution of salt must have interfered greatly 

 with the free transmission of heat through the widely and unequally dif- 

 fused immense heterogeneous »?!agHia formed by the whole J and the 

 evaporation of the solution must at the same time have been in a great 

 degree promoted and accelerated by the extensive surfaces presented 

 by the earthy matter. The maintenance, therefore, or even the pro- 

 duction, perhaps, of so high a temperature as 226'^, which is the boil- 

 ing point of saturated brine, until, at least, the whole or nearly the 

 whole of the water had been evaporated, must be regarded, under all 

 these circumstances, as a phaenomenon which it is scarcely possible 

 could have occurred ; or if ever it did occur, it must have been trans- 

 ient in its duration, and very limited in its extent. 



The abundant presence of the hoppers, therefore, in the American 

 saliferous rock, evinces, on the one hand, that igneous action, (how- 

 ever remote its focus) must have been concerned in the consolidation 

 of that rock ; while, in conjunction with the presence of the cubical 

 crystals, it shows, on the other hand, that the degree of heat to which 

 it was exposed could not have been very elevated, prior at least to the 

 evaporation of the water. 



How long this heat continued, to what extent it became augmented 

 after the evapoi'ation of the water, and how far it may have been 

 operative in giving the beds of rock-salt, such as those of Cheshire, 

 their present form, agreeably to the views of Hutton and Playfair, are 

 questions, involving the universal history of the new-red-sandstone 

 formation ; and constituting a subject of complicated inquiry, alto- 

 gether distinct from that of the foregoing remarks. But it may not 

 be irrelevant to observe, that if we adopt the theory whicli ascribes 

 the formation of the beds of rock-salt to the igneous fusion of that sub- 

 stance, it will be necessary to inquire, whether the salt formerly ex- 

 isting in the cavities of the saliferous rock, has been merely dissolved 

 out by water, as supposed above ; or whether it has been melted out 

 by heat, and diffused, when in a liquefied state, through the containing 

 and contiguous rocks, from which the water of the brine-springs may 

 subsequently have been impregnated. If the latter process has in 

 reality taken place, the heat by which the salt was fused, would at 

 the same time necessarily have indurated (as it were baked) the earthy 

 matter in which the crystals had been deposited ; a circumstance 

 which must have tended materially to preserve the regular form of 

 their im-pressions in the rock. 



As the importance of instituting a new and extensive series of che- 

 mical researches on the contents of rock-salt from every locality, has 

 been urged, in the paper on the existence of salts of potash in that 

 substance*, it seems expedient to add a remark or two in this place, in 

 reference to the utility of such an investigation in a geological point of 

 * See our last number, p. 415.— Edit. 



view. 



