farmers' and mechanics' journal. 



IVEISCELLANEOUS. 



Inflammation of Gunpowder. — We were pleased with the 

 caution used by a person in this neighborhood, in blasting rocks.. 

 He informed us that after the hole was drilled, he used no metallic 

 substance whatever in charging for the blast. A small twig of ash 

 or elder with the pith pushed out, formed a tube which connected 

 the priming with the charge. In ramming, he used a wooden rod 

 and a mallet. To show that this care is wise, and that it would 

 prevent many of the horrible accidents which often occur in charg- 

 ing rocks in the common way, we publish the following from Silli- 

 man's Journal. 



Powder Mills. — Although great care is taken to exclude from 

 these manufactories all articles of iron, and to substitute copper 

 and other metals, in the metallic parts of the machinery, which 

 will not strike tire, yet it is well known that explosions, attended 

 with disastrous consequences, arc very frequent. Excited by an 

 occurrence of this nature, M. Auhcrt, Colonel of artillery, was in- 

 duced, in conjunction with Capt. Tardy, to lesume some experi- 

 ments which he had unsuccessfully tried, to ascertain, whether 

 gunpowder would not explode by the shock of copper. The re- 

 sult of these renewals was, that powder would inflame by the 

 stroke of copper upon copper, or upon the alloys of copper. This 

 gave rise to further investigations, in presence of the committee of 

 safety, and it was ascertained that gunpowder could be exploded 

 by the stroke of iron upon iron j iron upon copper ^ copper upon 

 copper ^ iron upon marble ; and with suitable precautions even by 

 lead upon xoood. The experiments were successful both with Eng- 

 lish and French powder. The experiments most clearly show, 

 that in all the manipulations of a powder manufactory, all violent 

 shocks and percussions should be caretuUy avoided, since they 

 may occasion the disengagement of sufficient heat to produce the 

 inflammation of powder. [JB?J. d'' Encouragement, Juin, 1826. 



Black Dye and Ink prepared zviih Logwood. — The following is a 

 process for the preparation of a black dye, for which a patent was 

 taken out at Vienna, by Mr. Honig. Logwood is to be boiled 

 several times in water, and a little subcarbonate of potash to be 

 added to the decoctions, (he quantity being so moderated that it 

 shall not change the color to blue ; the stuff to be dyed is then to 

 be plunged into this bath. This stuff may be either animal or 

 vegetable. When it is well impregnated with coloring matter, it 

 is to be withdrawn, and, without being exposed to air, is to be in- 

 troduced into a solution of green vitriol, and left there until it has 

 obtained the desired black hue. In preparing the ink, the decoc- 

 tion of logwood is used in place of the infusion of galls. 



[(^uaiierhf Journnl. 



