\ 
On the pretended diffusion of Copper in nature. 67 
alcohol charged with fluo-silicic gas; in this case, the red color 
is obtained which characterizes sulpho-cyanid of iron, How- 
ever, this red color disappears in the presence of an alkaline 
fluorid; there is formed a white cloud composed of one of the 
before mentioned fluo-salts, and the liquid contains an alka- 
line sulphocyanid. Acetate of iron is equally discolored under 
these circumstances. On operating with fluorid of potassium 
and concentrated solutions, all the iron is precipitated in the 
condition of fluo-salt; with liquids more dilute, a little iron 
always remains in solution. 
hydrates of the organic bases. What I have just said of iron 
I compounds 
« 
* 
plays the part of an acid, I shall speak of it in greater detail 
~ 
