300 DESCRIPTION OF THE MUSEUM. 



lamellar or Venetian talc, the powder of which 

 renders the skin smooth and shining. It is co- 

 loured with the plant named carthamus, and 

 then sold as rouge. Before we quit this room, 

 we should observe between the windows a su- 

 perb vase of the brecciated porphyry of the 

 P^osges, and two very large groups of prismatic 

 crystals of colourless quartz. The following room 

 contains the inflammable substances and the 

 metals. Returning to the order of the numbers 

 on the cases, we find in the thirty-second those 

 substances which are combustible, but not me- 

 tallic. The principal is native sulphur, or sul- 

 phur free from all combinations. There are 

 some superb groups of translucid crystals, and 

 a beautiful series of varieties, given by M. Lucas, 

 and which he procured in his last journey in 

 Sicily and Italy. 



The diamond, which follows in the thirty- 

 third case, is placed amongst the combustibles, 

 next to the anthracite, or native mineral carbon, 

 because it burns without leaving any residue ;. 

 and the most exact experiments have proved, 

 that the diamond is only mineral carbon in its 

 purest state. Below the stage for study is a series 

 of diamonds, rough and cut ; the regular forms 

 of the first are the effect of crystallization. In 

 the same case are placed the different varieties 



