THE 



PHILOSOPHICAL MAGAZINE 



AND 



ANNALS OF PHILOSOPHY. 



[NEW SERIES.] 



JUNE 1830. 



LIII. Chemical Examitiatw7i of a Crystalline Substance from 

 the Zinc-foundry at Filistir ; together wit/i an Account of 

 some ancient Glass Beads coloured by Oxide of Copper. By 

 the Rev. Wm. V. Vernon, F.R.S.* 



THE substance of which I propose to give an account was 

 obtained, by my friend Mr. Marshall, from a zinc-foundry 

 belonging to M. Hitz, at Filisur in the Canton of the Grisons. 

 It is said to occur oozing out of the crucibles while the metal 

 is in a state of fusion ; and yet the specimen resembles a natural 

 mineral so much in its general appearance, that, without this 

 information, it might have been supposed to have come from 

 the cavity of a rock or the interstice of a mineral vein. The 

 structure is crystalline, and a few of the crystals in the hollow 

 parts of the specimen are extremely perfect ; they are regular 

 hexagonal prisms, terminated by similar pyramid st, transpa- 

 rent, amber-coloured, splendent, yielding with difficulty to the 

 knife: the specific gravity of the more perfectly crystallized 

 parts is 6'0, but that of inferior pieces is as low as S'iS. 



I placed a grain of the crystals, in powder, on platinum foil, 

 and heated it to redness. There was no loss of weight ; the 

 powder grew yellow when hot, and whitened again on cooling. 

 When a crystal was exposed to the reducing flame of the 

 blowpipe, it evaporated by degrees, and a white film spread 



• Read before the Yorkshire Philosophical Society, April 6, 1830 ; and 

 comiTiiinicatcil by the Author. 



t The pyramidal suminit is replaced in some of the crystals by a plane 

 at right angles to the axis of the prism. The angles which the lateral 

 planes of the prism make with each other were measured by Mr. John 

 Phillips with the reflective goniometer, and found to be 1~0°. 



N. S. Vol. 7. No. V2. June 18.30. 3 F over 



