Dr. Clarke's Analysis of a bituminous Limestone. 433 



6. The calcined residue being placed in muriatic acid, a solution 

 iiow took place both of the lime and of the alumine, and there 

 remained at the bottom of the vessel only an insoluble portion of 

 pure si/ex, in the form of a white powder, which when carefully 

 washed and dried weighed f of a grain. Deducting therefore this 

 weight of the silex, from the weight of the silex and alumine, which 

 remained in No. 4, after the combustion of the bitumen, the weight 

 of the alumine is ascertained ; which of course equals 8 T 8 ^ grains. 



From all the preceding observations, it is therefore evident that 

 the constituents of this limestone are as follow: 



Lime 49. 65 



Carbonic acid 40. 10 



Alumine 8. 80 



Silex — 60 



Bitumen — 60 



Water — 25 



100. . . 



And the valuable property of the mortar prepared from this 

 limestone, is owing to the presence and proportion of alumine ; and 

 to its property of rapidly absorbing water. 



