45$ Count Rumford^s Inquiry concerning the 
I plainly perceived that the experiment succeeded best, that 
is to say, that the gold was soonest revived , in those cases in 
which the solution was most diluted : one of the experiments, 
however, and which succeeded perfectly, was made with the 
solution so much condensed, that it was nearly at the point at 
which it became disposed to crystallize.* 
On examining, with a good microscope, the particles of 
revived gold which remained attached to the surface of the 
charcoal, after it had been dried, I found them to consist of 
an infinite number of small scales, separated from each other ; 
not very highly polished, but possessing the true metallic 
splendour, and a very deep and rich gold colour. 
The gold which attached itself to the inside of the glass 
tube, was in the form of a ring, about T r o °f an, inch wide, 
(badly defined however below,) and adhered to the glass 
with so much obstinacy, as not to be removed by rincing out 
the tube a great number of times with water ; it had, as has 
already been observed, a very high polish, when seen by re- 
flected light. 
Those who enter into the spirit of these investigations, will 
easily imagine how impatient I must have been, after seeing 
the results of these experiments, to find out whether gold 
could be revived from this aqueous solution of its oxide by 
means of charcoal, without the assistance of light, and merely by 
such a degree of equal heat as could be given to it in the dark. 
To determine that important question, the following experi- 
ment was made. 
* This agrees perfectly with the results of similar experiments made by the inge- 
nious and lively Mrs. Fulham e. (See her Essay on Combustion, page 124.) 
It was on reading her book, that I was induced to engage in these investigations ; and 
it was by her experiments, that most of the foregoing experiments were suggested. 
