72 Intelligence and Miscellatieous Articles. 



Eaton deduces the theory just stated ; repeating it in the Geological 

 Survey, as cited by Dr. Bigsby. But surely the foregoing are insuf- 

 ficient data for such a theory. The water-limestone is doubtless in- 

 timately pervaded with chloride of sodium, which the moisture of the 

 atmosphere, acting upon an exposed specimen, and the water of the 

 springs, acting upon the rock in situ, extracts and dissolves. Adopt- 

 ing this view of the subject, we should expect to discover in the brines 

 a portion of carbonate of lime, derived from the limestone ; and ac- 

 cordingly Mr. Chilton found that earthy salt, sometimes in consider- 

 able quantity, in the brine of all the springs he analysed ; and Dr. 

 Beck also found it in his analysis of the brine of Salina. The brines 

 of the Cheshire and Droitwich springs in England, on the contrary, 

 which arise from the direct solution of rock-salt, to which no carbo- 

 nate of lime is immediately contiguous, are either entirely free from 

 it, or contain only a very minute proportion. 



In Silliman's Journal, vol. xv. No. 2., for Jan. 1829, in a paper on 

 " gases, acids, and salts, of recent origin and now forming, on and 

 near the Erie canal," Mr. Eaton has again alluded to this subject, and 

 has mentioned a curious fact, which, as far as the reading in Geology 

 of the present writer has extended, has not hitherto been noticed in 

 the saliferous beds of any other part of the world. This is the oc- 

 currence, in manv localities, sometimes in the " calcareous slate" 

 and marle-slate of the " saliferous rock," and sometimes in the super- 

 incumbent " lias*," of innumerable moulds or cavities which have been 

 formed upon crystals of chloride of sodium ; as well upon cubic cry- 

 stals as upon the hollow inverted pyramidal aggregates of cubes, termed, 

 by salt-manufacturers, hoppers. Many of these cavities also present 

 every intermediate combination, from the mere hopper, to the solid 

 and complete crystal. " That the rock was deposited while in a soft 

 state," Prof. Eaton remarks, "upon the solid crystals, and the salt 

 was afterwards dissolved, leaving the space it occupied empty, seems 

 not to admit of a doubt." " But what changes," he continues, " have 

 taken place which should produce solid crystals at one time, and dis- 

 solve them at another ?" 



Now there appears to be no difficulty in explaining all this j indeed 

 the phaenomenon, interesting as it is, explains itself. The crystals 

 of chloride of sodium formerly existing in the strata, were doubtless 

 deposited, at the aera of the formation of the saliferous rock, by the 

 same agency, which, in other parts of the world, produced beds of rock- 

 salt ; and the salt has simply been dissolved out at a subsequent period, 

 by the percolation of water through the superincumbent strata, leaving 

 impressed in the rock cavities bearing the forms of the crystals. And 

 such, without doubt, has been one source of the brine-springs of this 

 districtf. 



Perhaps 



* So Mr. Eaton here denominates it ; but this stratum, as appears on 

 comparing his former with his present statement, is evidently the limestone, 

 subordinate to the saliferous rock, ah-eady mentioned. 



f In Townson's Hungary, (as quoted in Kidd's Geological Essay, p. 1 17,) 

 it is stated, that the lowest bed of marl in the great salt mines of Wielicza 



