Proportion of the ingredients.
The proportions of the three ingredients vary slightly all over the Continent and America, being as follows:—
| SALTPETRE. | CHARCOAL. | SULPHUR. | |||
|---|---|---|---|---|---|
| France | - | 75 | 12.5 | 12.5 | |
| Belgium | |||||
| Russia | 73.78 | 13.59 | 12.63 | ||
| Prussia | 75 | 13.5 | 11.5 | ||
| Austria | 75.5 | 13.2 | 11.3 | ||
| Spain | 76.47 | 10.78 | 12.75 | ||
| United States | 76 | 14 | 10 | ||
PRODUCTION AND PURIFICATION OF THE INGREDIENTS.
Production and purification of the ingredients.
The nitre is purified in a similar way to the new method employed at Waltham Abbey, though it is seldom obtained with so faint a trace of chlorides, owing probably to its being of an inferior quality, and of higher refraction when it is imported.
The sulphur is supplied to the manufactories in France in the form of roll sulphur, from Marseilles and Bordeaux, where there are very large refineries.
The charcoal is prepared from dogwood, alder, willow, hazel, and poplar, sometimes in pits, and occasionally in cylinders, as at Waltham Abbey. At Wetteren, and in some parts of France, it is distilled by the action of steam. The “charbon roux” taking its name from its brownish-red tinge, from being only partially burned, was used formerly more than now, as the powder made from it was found to injure and exert very pernicious effects upon fire-arms.