#0 Wooden Matches for Artillery , 
may be found in tbe composition of the two salts : ni- 
trate of lead contains .75 of its base, that of potash but 
A9. 
The rapid combustion of the wooden match is owing 
also to the facility with which the salts of lead are re- 
duced, when in contact with burning charcoal. If a 
hempen rope be boiled in a solution of acetate of lead, 
and afterward dried, it may be used as a match. It burns 
slowly like touchwood, and has a very bright coal. The 
oxide of lead, as the metal is reduced, gives out its oxi- 
gen to the carbon, and accelerates the combustion.* 
On comparing the specific gravity of wood with its sa- 
turation by salts, we find, that the lighter the wood, the 
more saline matter it absorbs into its pores, or the inters- 
tices of its fibres. Hence it appears to me we may in- 
fer, that it contains less carbon than a heavier wood in a 
given bulk ; and that its combustion will evolve less ca- 
loric, since the caloric emitted is in the ratio of the quart 
tity of oxigen combined with the combustible. It seems 
to me, that we might class different kinds of wood, as to 
their combustibility, by their absorption of salts ; and 
thus find which would be most advantageous to burn for 
domestic purposes, whether we would have a rapid com- 
bustion, or a stronger and more continued heat. These 
researches will form the subject of a particular work, 
which I purpose on all our forest trees. 
The wooden matches, compared with port-fires, have 
the following advantages. 
The port-fire lasts but three or four minutes. 
A match a yard long w ill bum three hours. 
The port-fire is liable to break in the boxes. 
The match is strong, and easily carried about. 
The port-fire throws out dangerous sparks : 
* We have a familiar instance of this in the popular experiment of burning a 
red wafer in the flame of a candle. 
