Analysis of CuproUtes. 165 



In a coprolite from Burdiehouse, analyzed by Mr Connell, 

 that accurate chemist could not detect the presence of fluorine. 

 In the coprolite analyzed by us, however, we had no difficulty 

 in detecting that substance, by the ordinary process. 



This interesting substance, when exposed to a high tempera- 

 ture, gives off water highly charged with bituminous matter, 

 and a small portion of ammonia ; this circumstance, taken in 

 combination with the occurrence of the phosphate of lime, proves 

 beyond the possibility of a doubt its animal origin.* 



2. Analysis of a Coprolite from Fifeshire. 



This coprolite differs considerably from the one which we last 

 examined, inasmuch as it contains a much greater proportion of 

 phosphate of lime, with a smaller quantity of carbonate. The 

 oxide of iron in this is a mere trace, whereas the Wardie copro- 

 lite contained a considerable portion. In this as well as in the 

 Wardie coprolite, we found very distinct traces of the presence 

 of the fluoric acid, as the accompanying glass shews.-f- The 

 organic matter which we obtained from this coprolite exhibited, 

 in a more unequivocal manner, its animal origin, than that got 

 from the other, for, when exposed to heat in a tube, it not only 

 gave off a water highly ammoniacal, but exhaled the peculiar 

 smell of decomposing animal matter at a high temperature. In 

 this as well as the other we found an appreciable quantity of 

 carbonate of magnesia, and we detected besides a small portion 

 of phosphate of magnesia. 



The following is its composition : — 



Alatter insoluble in muriatic acid, and chiefly organic, . . 3.380 



Carbonate of lime, 24.255 



Carbonate of magnesia, 2.888 



Phosphate of lime, C3.59«! 



AVater, 3.328 



Phosjihate of magnesia,) 

 Oxide of iron, I 



Oxide of manganese, j Trace. 



Fluoric acid, | 



97.447 

 •MrConuell informs me he has, since the publication of his analysis of co- 

 prolite, found, as Dr Gregory and Mr Walker had previously done, fluoride 

 of calcium in the coprolite of Burdiehouse, and also in the fish scales, 

 bones, and bony rays from the same quarry. 



f On tlie specimens of glass exhibited to the Society, letters and figures 

 were beaulifullv etched bv the fluoric acid from the coprolite. 



