MODE VII. MARLIT*. 475 



often with open intervals; and at Sutherland is 

 the common building-stone. 



Coral rock, from Australasia. 



Madrepore rock, from Sutherland and Pe- 

 terhoff. 



MODE VII. MARLITE. 



The combination of this substance is the same Description, 

 with that of marl, the calcareous earth being 

 mixed with a considerable proportion of argil. 

 Some marbles, which contain from 15, to 30 or 

 more of argil, are properly marlites $ and they 

 are apt to decompose in the open air. Such is 

 the green Campan of the Pyrenees, which also 

 contains a considerable proportion of magnesia. 

 Several of the Russian marbles also contain clay, 

 but mixed with a still larger proportion of silex. 



The celebrated pictorial marble of Florence, 

 which imitates ruins, and sometimes trees, is 

 properly a marlite. 



" This marble presents angular figures of a Marble of 

 yellowish brown, on a base of a lighter tint, and 

 which passes, in diminishing, to a whitish grey. 



" Seen at a certain distance, slabs of this 

 stone resemble drawings done in bistre. One is 

 amused to observe in it kinds of ruins : there, it 



