and Detonating Matches. 131 



The process by fusion, performed at some of the public 

 works in this country, does not afford a return at all compa- 

 rable with that of the above French process, though a much 

 better article is operated upon in England. After two melt- 

 ings of grough sulphur (as imported from Sicily or Italy), 

 eighty-four per cent, is the maximum amount obtained, the 

 average being probably under eighty ; while the product is 

 certainly inferior in quality to that by distillation. 



3. On the Charcoal 



Tender and light woods, capable of affording a friable and 

 porous charcoal, which burns rapidly away, leaving the small- 

 est residuum of ashes, and containing therefore the largest 

 proportion of carbon, ought to be preferred for charring in 

 gunpowder- works. 



After many trials, made long ago, black dogwood came to be 

 preferred to every plant for this purpose ; but modern experi- 

 ments have proved, that many others afford an equally suitable 

 charcoal. The woods of black alder, poplar, lime-tree, horse- 

 chesnut, and chesnut-tree, were carbonized in exactly similar 

 circumstances, and a similar gunpowder was made with each, 

 which was proved by the same proof-mortar. The following 

 results were obtained : 



Toises. Feet. 



Poplar mean range 113 2 



Black alder 

 Lime 



Horse-chesnut 

 Chesnut-tree 



110 4 



110 3 



110 3 



109 



By subsequent experiments confirmatory of the above, it has 

 been further found, that the willow presents the same advan- 

 tages as the poplar, and that several shrubs, such as the hazel- 

 nut, the spindle-tree, the dogberry, the elder-tree, the com- 

 mon sallow, and some others, may be as beneficially employed. 

 But whichever wood be used, we should always cut it when full 

 of sap, and never after it is dead; we should choose branches 

 not more than five or six years old, and strip them carefully, 

 because the old branches and the bark contain a larger propor- 

 tion of earthy constituents. The branches ought not to exceed 



K2 



