Fort St. Frederic. 21 



raent could feparate them. The {lone was 

 very hard and compad:, and the grains of 

 quartz looked very line. 



2. Some pieces ccnfifted of grey parti- 

 cles of quartz, black glimmer, and horn- 

 flone, together with a few particles of fpar, 

 which made a very clofe, hard, and com- 

 pad: mixture, only differing from the for- 

 mer in colour. 



3. A few of the flones confifted of a 

 mixture of white quartz and black glim- 

 mer, to which fome red grains of quartz 

 were added. The fpar (quartz) was moft 

 predominant in this mixture, and the glim- 

 mer appeared in large flakes. This ftone 

 was not fo well mixed as the former, and 

 was by far not fo hard and fo compact, 

 being eafily pounded. 



The mountains on which fort St. Fre- 

 deric is built, as likewife thofe on which 

 the above kinds of ftone are found, confifted 

 generally of a deep black lime-ftone, lying 

 in lamellae as flates do, and it might be 

 called a kind of flates, which can be turn- 

 ed into quicklinie by fire *. This lime- 

 ftone is quite black in the inflde, anc^, 

 when broken, appears to be of an exceed- 

 B 3 ing 



* Marmor fchiftofum, Linn. Syft. III. p. 40. Marmor u^ 

 nicclor nigrum. Wal'. Min, pag. 61. n. 2. Lime-Jlate! ,fckijlut 

 ^akaniiSx> Forft. Inttod. to iViin. p. 9. F. 



