MODE I. TALC. 305 



been improperly bestowed. The gold and silver 

 mica of many writers seem rather to be talcous or 

 micarel ; as the large brown talc sometimes verges 

 to a golden colour, and it is suspected that no 

 iron is found in either. 



The Muscovy talc has been used instead of 

 glass for windows and lanterns, especially on 

 board of ships, where it is not subject to be broken 

 by the firing of cannon*. It was formerly con- 

 founded with laminar selenite ; and both were 

 called glades Maries, or the ice of the Virgin 

 Mary ; as the latter is still called by the labourers 

 at Montmartre pierre de Jesus, because it served 

 as a glass before little prints of the Saints. 



Aspect 1. Large foliated talc. White, from 

 the Uralian mountains. 



Greenish, from Tyrol. 



Brown, from the Uralian mountains. 



The same, with metallic lines, red, green, and 

 blue, perhaps from the vicinity of copper-mines. 



Aspect 2. Undulated. Of various tints, from 

 same countries. 



* It is the mica memlranacea of Wallerius, which he says was 

 brought from Archangel. 



VOL. I. X 



