“ 
290 Chemical Preparations. 
mufiled furnace, taking care to knead the mass assiduously, and 
remove the plate as often as the bottom of the mass became pretty 
slippery. ; 
By the previously melting together of the nitre and carbonate of 
potash, a more intimate union of these substances was effected than 
could possibly be made by mechanical means, or by the slight melt- 
ing which was admissible in the after process; and by the final melt- 
ing of the whole upon a ¢iick iron plate, I was enabled to conduct 
the business with facility and safety. 
The melted mass, after being cold, is as hard and porous as pum- 
ice stone, and is grained with difficulty ; but there is a stage when it 
is cooling in which it is very crumbly, and it should then be powder- 
ed upon a board, with a small wooden cylinder, and put up hot, with- 
out sorting the grains or even sifting out the flour. 
In filling an order for one ton of the powder, I blew up fifty pounds 
of the composition in the grinding mill, and I then exchanged the 
manufacture of it for that of percussion powder. 
Although it was eight and a half times quicker in burning, yet in 
an equal charge it did not project a ball with more than one half the 
force of black powder. At first, I was timid in using it in the barrel 
of the gun, but I'soon found that quickness was not power, and that 
the power of the powder in projecting a ball was in proportion to the 
bulk of the fame when burned in open air. The same I have found 
true with fulminating mercury. I have many times used it in the 
barrel of a rifle, in free doses, and have always found the ball to be 
projected by a feeble force. From the small amount of permanent 
gases evolved in burning this powder, compared with those from 
gunpowder, and the rapidity with which it is done, the force 1s, prob- 
ably, after the first instant, a receding or diminishing force ; but m 
burning common powder the resulting gases are of greater amount, 
and the inflammation is not complete, even when the ball leaves the 
gun; hence the power at first applied to the ball, whilst it acts upon 
it, is a constantly increasing one. 
For nearly three years, in which I hunted very much, I used yel 
low powder exclusively, and arrived at the conclusion, that for throw" 
ing ball and shot, and that with accuracy and steadiness, NO other por” 
der could compete with it. It attracts moisture from the atmosphere 
greedily, and is soon decomposed. Hunters were in the habit 0 is 
rying the powder in well corked phials, and throwing out the priming» 
if they liad no occasion to use it, once or twice a day- 
