XXIII. On Cryolite. 

 By Professor Jameson, 



iRtad Wth Feb. 1809 3 



Several years ago, a Danish Missionary brought 

 a collection of minerals from West Greenland to 

 Copenhagen ; and among these were a number of 

 specimens of a white-coloured fossil, which passed 

 for lamellar heavy-spar. This substance lay un- 

 noticed for some years^ until the Danish natura- 

 list Abildgaard, struck with its resemblance to 

 heavy-spar, and its comparatively low specific 

 gravity, determined to analyse it. He found it to 

 contain alumina, fluoric acid, and a small portion 

 of potash # . Specimens were soon afterwards sent 



og 



* From its resemblance to ice, it was named Cry 

 ©lite, 



