chemical Properties attributed to Light, 463 
which was about half filled, being closed with a good cork, well 
secured in its place, was exposed to the action of the direct rays 
of a bright sun. 
A pellicle of revived gold, in all its metallic splendour, began 
almost immediately to be formed on the surface of the aqueous 
liquid, and soon covered it entirely; and, at the end of two hours, 
the whole of the oxide was completely reduced, as was evident 
from the appearance of the ether, which became perfectly co- 
lourless. 
On shaking the phial, the metallic pellicle which covered the 
surface of the aqueous liquid was broken into small pieces, which 
had exactly the appearance of leaf gold, possessing the true 
colour, and ail the metallic brilliancy, of that metal. 
On suffering the phial to stand quiet, the aqueous liquor and 
the ether separated, and most of the broken pieces of the thin 
sheet of gold descended to the bottom of the phial : the remain- 
der of them floated on the surface of the aqueous liquid ; and 
the ether, as well as the aqueous liquid, appeared to be perfectly 
transparent and colourless. 
By the length of time which was required for the ether and 
the aqueous liquid to separate, I thought I could perceive that 
the ether had lost something of its fluidity; but, as this was an 
event I expected, it is the more likely, on that account, that I 
was deceived, when I imagined I saw proofs of its having taken 
place. 
On removing the cork, after the contents of the bottle had 
been suffered to cool, there was no appearance of any consider- 
able quantity of air, or other permanently elastic fluid, having 
been either generated or absorbed, during the experiment. 
Finding that the oxide of gold might be so completely and 
