284 DESCRIPTION OF THE MUSEUM. 



stone, had no windows; and was only illumi- 

 nated by the light that passed through the w alls. 

 Besides these, we observe in the cabinet the 

 white laminar variety from Sicily, remarkable 

 for its beautiful pearly lustre ; the fibrous variety, 

 of a shiny and silky whiteness, used in jewellery ; 

 the niviform, which has the appearance of a 

 snowball ; lastly, the compact variety, or gyp- 

 sous alabastar, employed in making statues and 

 ornamental vases. 



In the tenth case is the anhydrous sulphate of 

 lime^ which only presents one remakable variety, 

 the lamellar, of a sky-blue colour, and called 

 Wurtemberg marble. There is a beautiful po- 

 lished slab of it, which was presented to the 

 Museum by the King of Wurtemberg. 



The nitrate of lime is the substance daily formed 

 on the sides of damp walls, and obtained by 

 washing old plaster for the making of saltpetre. 



The arseniate of lime follows immediately ; 

 its name indicates the presence of arsenic acid 

 in it ; it is only known to mineralogists. It has 

 been called pharmacolite, or poisoned stone. It 

 owes its pink hue to the presence of cobalt. 



The sulfate of barytes, which occupies the 

 eleventh and twelfth cases, is, next to the carbo- 

 nate of lime, the species most abundant in regular 

 forms. The stage for study presents a consider- 







