OF THE FAROE ISLANDS. 237 



cavities were three feet in diameter, and entirely lined with large 

 crystals of stilbite ; but .the most interesting, were between 

 Quivig and Westmanhavn. In one, we observed the mesotype, 

 in long acicular crystals, but so extremely slender, that it 

 was quite impossible to detach them entire from the rock. 

 In another, we found the same substance, but in a more tangible 

 form. This cavity was about two feet wide, eighteen inches 

 deep, and nine high, in a perpendicular rock, about ten feet 

 from the base, which was washed by the tide. By means of 

 a ladder, we succeeded in reaching this repository, and found 

 the whole interior coated with aggregated groups of stilbite, 

 having only the crystallised acuminations visible, of an opake 

 yellowish-white colour, and varying from an inch to an inch 

 and a half in thickness. Upon this ground were disposed nu- 

 merous groups of mesotype, radiating from a centre, and shoot- 

 ing from the surface, an inch to an inch and a half in length, 

 in clear, transparent, well-defined prisms, of a rectangular 

 form, terminated with a flat four-sided pyramid, the variety 

 pyramidee of Hauy, and varying in size from a hair to a line 

 in thickness. It was a mortifying circumstance to be obliged 

 to destroy any part of this very magnificent specimen, in de- 

 taching it from the rock ; a circumstance, however, totally un- 

 avoidable. I succeeded in obtaining several very good speci- 

 mens, and by gluing them carefully to the bottom of a box, was 

 very fortunate in preserving them in all their natural beauty. 



This is the Mesotype of Hauy, and the Nadelstein of Wer- 

 ner ; it varies entirely from the Apophyllite formerly noticed ; 

 in place of a distinct foliated cleavage, cutting the axis at 

 right angles, with a pearly lustre on its terminations ; it pre- 

 sents a vitreous fracture, without the appearance of any regu- 

 lar cleavage, and an uniform lustre in all directions. Fragments 

 of Mesotype dissolve in nitric acid, and form a clear transpa- 

 rent 



