Photography. 397 
f opaque sulphur may not form. The pa- 
. At the required moment, the 
tive, and exposed to the light for 
ve minutes on a dark day. When 
a 
Nothing ap upon the surface of the paper whien it is removed 
from the slide. It is then put over a mercury bath at the bottom of 
vad are placed some grams of this metal. The sulpburized paper 
m 
the camera is then ex at the distance of eight centimetres above 
the mercury, (which is heated meantime,) sus on a frame of pa- 
ce to the mercury, is the prepared paper. The vapor " 
bines with the pertions of go ee which have received the influence 
the sun’s rays, forming a yellowish brown sulphuret of mercury, which 
Perfectly reproduces the details of the impression. The picture is then 
by a film of varnish-gum, or albumen, to preserve It. 
This is the process of M. Salmon, of Chartres. 
. False Diamond.—In 1857, several men of science at Paris, we 
i e water, cut like the regent diamond, 
a di characteristics 
The owner had 
