66 MINERAL RICHES OF OUR VICINITY. 



one inch thick, and quite colourless and transparent, 

 have been dug out at Devil's Point. Besides these, 

 probably 200 varieties of calc spar may have been, at 

 different times, collected from our quarries, and many 

 others have doubtless escaped hitherto unnoticed. 

 They may be classed as 



A. -The Rhomb, and its numerous modifications. 

 B. The Prism, and its not-less multifarious va- 

 rieties. . 



C. The Pyramid, offering more diversities than 

 both the other classes together. 



D. Crystals, intermediate between the Rhomb and 

 the Prism. 



E. Those intermediate between the Rhomb and 

 the Pyramid. 



F. Intermediate between the Prism and the Pyra- 

 mid. 



G. Compounds of A, B and C, connected. 

 Any person, in his occasional walks through the 

 quarries, may furnish himself with many of these 

 varieties. 



Next to the crystals of the limestone formation, 

 come the Stalactites : these are capricious and uncer- 

 tain in their forms, and not, therefore, very capable of 

 classification. The ordinary figure is that of a long, 

 inverted cone, spreading wide at the base, formed by 

 the continual dropping of water, charged with calca- 

 reous matter, from a pendent spot in the roofs of 

 caverns (such as abound in the lime rocks). Some of 

 the water evaporates as it trickles down, and thus 

 forms, and continually increases, the stalactite. The 

 regular form most abundant after this, is that of a 

 tube the size and colour of a quill, but sometimes a 

 foot or more in length. This is difficult to detach, 

 without fracture, being exceedingly brittle. Between 

 these two forms are many irregular varieties, some of 

 them peculiarly grotesque, and even ludicrous. But 

 it would occupy many pages to describe even the lead- 

 ing features of calcareous stalactite, and only one other 

 variety of it, the most beautiful of the whole, shall be 



