55 



TAB. CXXX. 



PLUMBUM sulphatum. 

 Crystallized Sulphate of Lead, 



Div. 1. Crystallized. 



1 his is one of the set of modifications of Sulphate of Lead 

 which does not appear to have been noticed in any collec- 

 tion but my own, and shows a curious change as to the 

 formation taking place by means of spiculae. The inner 

 part of the crystals are of the primitive octaedron, appa- 

 rently rounding to a new modification by decomposition, 

 and forming spiculae from the mutual bases of the two 

 pyramids of the octaedron. — This seems quite new to the 

 mineralogical world : however, I have Carbonate of Lead 

 in dodecaedral crystals, looking as if decomposing, with 

 spiculae attached in a particular manner. 



