ANALYSIS OF LITHOMARGE. 177 



vious to the fenfes, is in the colour, and fmooth 

 iliining furfucc of the Lcmnian earth. 



Tiic fame obfervation may be made on their 

 properties, cither in fire or water. 



With regard to their competition, the differ- 

 ence in that rcfpccl ulfo is milling. They 

 have all the fame proximate principle*;, and va- 

 ry in nothing but the proportions of them. But 

 that \ve may prefent a clearer view of their fe- 

 vcral qualities and relations, we have drawn up 

 the following table in which the weights of each 

 principle are cxprcffed, in hundred parts, under 

 the head of its particular earth. 



TABLE. 



A Centenary J Lcmnian Ofmundic Hampfhirt 



contains of 3 carth - carth * earth - 



Siliceous Powder 47.0 <5o.o 51.8 



Aerated Lime 5.4 5.7 3.3 



Aerated Magncfia 6.2 0.5 0.7 



Argillaceous Earth 19.0 xi.i 25.0 



Calcined Iron 5.4 4-7 3-7 



Moid voiat. matter 17.0 18.0 15.5 



In the natural fyflcm therefore, ofCronftedt, 



the Hthomargaj are ranked as a particular diilindl 



fpccies of clay ; although the proportion of mag- 



nefia in two varieties in exceedingly fmall. But 



M this 



