268 Mr. Smithson’s Account of a Discovery , &c. 
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 colouring 
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 substance, 
and blended with it, have not allowed of more qualities 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 by 
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. 
I am, &c. 
JAMES SMITHSON. 
Cassell in Hesse, 
March 2d, 1806. 
