PHYSICAL AND LITERARY, sz 



and had been expofed time immemorial 

 to the open air, I found a thin white ef- 

 florefcence. In many places, where wa- 

 ter trickled down frooi the rocks above, 

 xnofs, to the thicknefs of fome inches, 

 had been in time accumulated, and was 

 now crufted over with a hard white 

 fnbftance. Below this cruft, the diffe- 

 rent plants of mofs were found difpofed 

 in a very regular manner, and foldered 

 together by a fubfliance fimilar to the 

 crult. Here I expeded to have found 

 the fait of marie , but could not, by any 

 treatment, difcover the fmallefl indication 

 of it. The mineral acids, after a very 

 briik efPervefcence, diflblved entirely both 

 the effervefcence from the furface of the 

 rock, and the matter which adhered to 

 the mafs. From this circumflance it 

 appears, that thefe fiibftances confilfed 

 jfolely of the calcarious earth of the 

 marie, freed from the other earths, by 

 the moifture, &c. whofe action it had 

 for many years undergone. 



These marles were expofeJ alone to 

 the air. Whether, when incorporated 



with 



