TAB. XCV. 



BARYTES sulfata. 

 Sulphate of Barytes. 



Class 2. Earths. Order l. Homogeneous. 



Gen. 6. Barytes. Spec. 2. Sulphate. 



Div. 1. Crystallized. 



This curious specimen was sent me from Cumberhead lead 

 mine, at the head of the Nethan river, in Ayr-shire, by 

 G. Laing, Esq. It is remarkable for the crystallized sul- 

 phate of barytes being immersed in amorphous sulphate of 

 barytes. Not having before seen a fracture that indicates 

 the integrant molecule, we are glad to make use of this 

 specimen to show the form of one. 



It is certainly very rarely to be fractured parallel to all its 

 faces, some of which are not at all to be seen, and it should 

 seem that Haiiy had only observed them by the scintilla- 

 tions within the crystal. To explain the nature of the 

 crystals formed in the upper figure, we have drawn a 

 distinct outline in the middle one, including the nucleus, 

 to show its situation. It will be easily seen that the perpen- 

 3 



