The Chemistry of Powder and Explosives - Sciencemadness Dot Org

FLASHLESS CHARGES AND FLASHLESS POWDER 325
the enemy can see its muzzle. In the daytime, Vorlage must
be used only when the weather is so dark that the flashes of
the shots without them are more visible than the clouds of
smoke which they produce. The opaqueness of the background
against which the battery stands out or the obscurity
of the setting which surrounds it are also at times of a kind
to justify the use of Vorlage in the daytime.
The anti-flash bags reduced the range by 4.5 to 8%.
Fauveau and Le Paire -"* studied the anti-flash effect of potassium
chloride and of other salts and concluded that the lowering
of the temperature of the gas which undoubtedly results from
their volatilization and dissociation is insufficient to account for
the extinction of the flash. Prettre 24 found that the chlorides of
sodium and of lithium, and other alkali metal salts which are
volatile, had the same effect as potassium chloride. He found
that small amounts of potassium chloride, volatilized in mixtures
of carbon monoxide and air, had a powerful anti-oxidant action
and a correspondingly large effect in raising the temperature of
inflammation of the gas. Some of his results are shown in the
table below. He found that potassium chloride was without effect
MILLIGRAMS OF KC1
PUB LITER
OF GASEOUS
MIXTURE
00
04
OS
07
10
13
20
2.5
30
3.5
TEMPLRATURK ( °C ) OF INFLAMMATION OF A
CONTAINING
248% CO 441% CO 673% CO
656 657 680
750 800
730
820
810 900
850 1020
790
810
890
970
1010
950
1000
upon the temperature of inflammation of mixtures of hydrogen
and air.
The French have used anti-flash bags (sachets antilueurs)
filled with the crude potassium hydrogen tartarate (about 70%
cit.
. at.
. . .