Being merely a loose mechanical mixture of three substances with different specific gravities, serpentine powder had a tendency, when shaken in transport, to resolve itself into three strata, the heaviest substance (the sulphur) settling down to the bottom, and the lightest (the charcoal) remaining at the top. This meant, practically, that on coming into the enemy’s presence the ingredients had to be incorporated afresh. To save trouble, and to avoid the danger of a second mixing, it was for a long time customary to carry the ingredients separately,[427] or, at least, to carry the charcoal apart from the saltpetre and sulphur. There was another argument, however, in favour of this course. While serpentine powder, however tightly secured, gave out a large quantity of impalpable dust which might cause an explosion at any moment, no explosion was possible so long as the ingredients were kept asunder. But whatever was the reason for resorting to such an expedient, it is evident that the remedy was nearly as bad as the disease. Serpentine powder had another drawback,—it required very careful ramming home. “Thrust the pouder home fair and softly,” says Whitehorne.[428] “The powder rammed in too hard and the wad also,” says Bourne in 1587, “it will be long before the peece goeth off.... The powder too loose ... will make the shotte to come short of the mark.... Put up the powder with the rammer head somewhat close, but beat it not too hard.”[429] By beating it too hard the interstices between the particles through which the flame permeated the charge were diminished in size, and if beaten sufficiently hard the mixture tended to become a solid which burned away without exploding. Finally, the combustion of serpentine, at the best, was so slow that a large volume of its gas escaped wastefully through the vent.