290 Chemical Preparations. 



muffled 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 efiected 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 thick 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 flame 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 is, prob- 

 ably, after the first instant, a receding or diminishing force ; but iu 

 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 pow- 

 der could compete with it. It attracts moisture from the atmosphere 

 greedily, and is soon decomposed. Hunters were in the habit of car- 

 rying the powder in well corked phials, and throwing out the priming, 

 if they had no occasion to use it, once or twice a day. 



