through a colorless prism, it is refracted, and forms, when thrown on
a wall or screen, a broad band of colored light,-- red, orange, yellow,
green, blue, indigo, and violet,-- which is known as the prismatic
or solar spectrum.
ARTIFICIAL DIAMONDS.
We find a report in French journals that
M. Gannal has succeeded in obtaining crystals,
having all the property of the diamond, through the mutual reaction of
phosphorus water and bisulphide of carbon upon each other for the space
of fifteen weeks.
The crystals were found to be so hard that
no file would act upon them. They cut glass like ordinary diamonds,
and scratched the hardest steel. In brilliancy and transparency they
were in no way inferior to the best jewels, and some possessed a
lustre surpassing that of most real stones.
For reference we record the cost of materials
for flint-glass, say in 1840 to 1845, as follows:--
| Litharge, or red lead, cost . .
| 6½ |
cts. |
per lb. |
| Pearlash,
| 6 |
" |
" |
| Nitre,
| 6 |
" |
" |
| Silex,
| 0½ |
" |
" |
|
