12B 



It seems to be 

 produced by 

 decay of ga- 

 lena. 



MENACANE, AND ITS ORES. 



In dilute white acid of nitre, it becomes of a coffee 

 colour. On the addition of a little sugar, this brown calx 

 dissolves, and produces a colourless solution. 



By putting it into marine acide with a little leaf gold, the 

 gold is soon entirely dissolved. 



When it is inclosed in a small bottle with marine acid, and 

 a little bit of paper tinged by turnsol is fixed to the cork, the 

 paper in a short time entirely loses its blue colour, and be- 

 comes white. A strip of common blue paper, whose colour- 

 ing matter is indigo, placed in the same situation undergoes 

 the same change. 



The very small quantity which I possess of this ore, and 

 the manner in which it is scattered amongst another sub- 

 stance, and blended with it, have not allowed of more quali- 

 ties being determined, but I apprehend these to be sufficient 

 to establish. its nature. 



This native minium seems to be produced by the decay of 

 a galena, which I suspect to be itself a secondary produc- 

 tion from the metallization of white carbonate of lead hy 

 hepatic gas. This is particularly evident in a specimen of 

 this ore which I mean to send to Mr. Greville, as soon as I 

 can find an opportunity. In one part of it there is a cluster 

 of large crystals. Having broken one of these, it proved 

 to be converted into minium to a considerable thickness, 

 while its centre is still galena. 



' -. lam, &c. 



JAMES SMITHSON. 



CasseU'in Hesse, 



March 2d y 1806. 



X. 



Jn Account of a neio semi-metallic Substance, called Menu- 

 cane, audits Ores. Bij the late G. Mitciiel, M.B.'^ 



natural SlNCE 



The natural OlNCE the discovery of Menacane by Mr. Gregor, the 



history of me- ,. . ... . ,. ,, ,.,,,• , , 



nacane has distinguishing properties Of the peculiar metallic substance it 



been little at- 



''''^"^ '''■ ' .^Ji iri.h Tramactions, Vol. X. 



contains 



