Organic Remains of Burdiehouse. 287 



A portion from a different part of this coprolite yielded 84.17 

 per cent, of phosphate of lime. 



It thus appears that the proportion of phosphate of lime, the 

 principal constituent of these remains, is pretty uniform, in so 

 far as the examination extended. A little variation occurs in 

 the relative quantity of the other constituents. Of these last, 

 the bituminous matter is certainly derived from the matrix ; and 

 it seems probable that the proportion of the carbonate of lime is 

 also slightly influenced by the limestone, as I shall afterwards have 

 occasion to shew. The proportion of phosphate of lime is much 

 greater than in the Has coprolites, in which it appeared to vary, 

 according to Dr Prout, from only ^th to f ths of the whole ; 

 whereas in those of Burdiehouse it amounts to about f- ths *. 



On finding the bituminous matter in the coprolites, I sub- 

 jected the limestone to the same process, to separate the bitumen 

 from it. A portion of the limestone matrix of the coprolite 

 first analyzed was dissolved in diluted muriatic acid, and the 

 undissolved dark flocky matter collected on a filter, washed, 

 and dried at the temperature of 212°. It then contained one- 

 half of earthy matter, and hence was not so black and glossy as 

 that from the coprolites, nor did it fuse on the application of 

 heat ; but, when heated in the open air with the contact of 

 flame, it took fire and burned with flame ; and, when heated in a 



* With reference to an analysis lately published by Dr Gregory and Mi- 

 Walker, (Edin. New Phil. Jour., Jan. 1835,) of a coprolite described as embedded 

 in a rolled mass of clay-iron from Burdiehouse, it is necessary to observe, that this 

 coprolite appears to have been extremely impure, containing only 10 per cent, of 

 phosphate of lime, and much foreign matter, such as sulphuret of iron, and large 

 quantities of carbonates of lime and magnesia. It is essential, therefore, to draw 

 a marked line of distinction between coprolites in ironstone or shale, and those di- 

 rectly embedded in the limestone of Burdiehouse, to which last alone my analyses 

 refer. I have seen coprolites from the shale of Burdiehouse, but I have never hap- 

 pened to see any from that locality, either in ironstone or in rolled masses. 



