THE OPERATIVE CHEMIST. 
488 
quently better adapted to that intimate combination of the 
ingredients necessary for the strength and durability of 
gunpowder. 
A manufacturer of gunpowder ought never to use sul 
phur which he has not purified and sublimed himself. The 
best method of doing this is by melting it in an iron pot, 
over a gentle coal-fire which does not blaze, and straining 
it through a double linen cloth. The operation must be 
repeated till there appears little or no residuum. When 
sulphur is bought in a prepared state, it is frequently adul 
terated with wheat flour, which, in moist or hot climates, 
readily induces fermentation, and irrecoverably decomposes 
the powder. Inattention to this circumstance is a principal 
cause of British gunpowder being less durable now than 
formerly. 
After an accurate examination of powder manufactured 
according to the most approved practices of Europe and 
Asia, together with the numerous variations of the chemist, 
Mr. Napier found it beyond his experience to give a decided 
preference, as he had seen them all succeed and fail. He 
therefore recommends that the proprietors of powder mills 
should manufacture a small quantity of powder from each 
fresh assortment of materials. In doing this, the following 
canon, which is borrowed from the French fire-workers, 
and established by experiments, may be found useful. Begin 
with 48 ounces of nitre, añd nine ounces of charcoal ; these 
will explode without sulphur. Increase the quantity of 
charcoal till the most forcible combination of those two in 
gredients is discovered, which will commonly happen at 
between 12 and 16 ounces of charcoal to the 48 ounces of 
nitre. To this composition let sulphur be added, beginning 
with half an ounce, till the strongest explosion is found; 
which will be when the proportion of this ingredient to the 
above is from 2¾ to 3¼. Finally let the dose of charcoal be 
diminished, till the composition no longer gains in the 
eprouvette. This will commonly happen when the propor 
tions of the three materials stand as follow :—nitre, 48 
ounces; charcoal, 8½ to 9½; sulphur, 2¾ to 3¼. 
The manufacturer, by adopting this method of ascertain 
ing their qualities, however troublesome it at first appears, 
will in the end be a considerable gainer. There are various 
opinions respecting the liquid most eligible to moisten the 
ingredients, during the process of preparing them for the 
mill. Urine, vinegar, spirit of wine and water, plain water, 
have severally been recommended for this purpose. Mr,