4^>o Count Rumford’s Inquiry concerning the 
used were specifically heavier than water, and sunk in it, to the 
bottom of the containing vessel. 
Having been so successful in my attempts to reduce the 
oxide of gold, by means of charcoal, in the moist way , I lost no 
time in making similar experiments with the Oxide of silver. 
Experiment No. 11. A solution of fine silver, in strong ni- 
trous acid, was evaporated to dryness, and the residuum redis- 
solved in distilled water. 
A portion of this solution, (which was perfectly colourless,) 
diluted with twice as much distilled water, was poured into a 
phial containing a number of small pieces of charcoal; and the 
phial, being well closed with a new cork stopple, was exposed 
to the action of the sun's rays. 
In less than an hour, small specks of revived silver began 
to make their appearance on the surface of the charcoal ; and, 
at the end of two hours, these specks became very numerous, 
and had increased so much in size, that they were distinctly vi- 
sible to the naked eye, at the distance of more than three feet. 
They were very white, and possessed the metallic splendour of 
silver in so high a degree, that when enlightened by the sun’s 
beams, their lustre was nearly equal to that of very small dia- 
monds. 
The phial, which was in the form of a pear, and about i|- 
inch in diameter at its bulb, was very thin, and made of very 
fine colourless glass ; the aqueous solution was also perfectly 
transparent and colourless ; and, when the contents of the 
phial were illuminated by the direct rays of a bright sun, the 
contrast of the white colour of these little metallic spangles 
with thd black charcoal to which they were fixed, and their 
