of Boston and its Vicinity, 

 Chymical Characters, 



141 



It is infusible before the blowpipe ; but it is soluble in nitrick 

 or muriatick acid with very slight effervescence, and it is precipi- 

 tated by ammonia. 



Geological Situation and Locality. 



t 



It occurs in small quantity disseminated in Chelmsfordite and 

 Limestone at Chelsmford. 



SPECIES VL.— CAR BOBCAT E OF LIME, 



Of this mineral the following subspecies and varieties occur, viz 



Subspecies I. — Calcareous Spar. 



Calcareous Spar, Cleaveland, p. 148. Calc Spar, Jameson, vol. i. p. 488. Conv 

 mon Spar, Kinvan, vol. i. p. 86. Carbonate of Lime, dikin, p. 174. 



Variety !.< — Crystallized Calcareous Spar. 



External Characters, 



L 



Its colours are white, and yellowish white. 



Its lustre is shining and glistening, and is between vitreous 

 and pearly. 



*i 



It is translucent, and sometimes slightly opaque. 



It is crystallized in acute rhombi, and the crystals are small 

 and very small, united by their edges and faces j surfaces of the 

 crystals slightly striated, 



I J 



It is semi-hard. 



The fracture is straight, foliated, with a threefold cleavage par- 

 allel to the faces of the crystals. 

 It is brittle, 



19 



