Gunpowder - Serpentine

Serpentine

The original dry-compounded powder used in fifteenth century Europe was known as "Serpentine", either a reference to Satan or to a common artillery piece that used it. The ingredients were ground together with a mortar and pestle, perhaps for 24 hours, resulting in a fine flour. Vibration during transportation could cause the components to separate again, requiring remixing in the field. Also if the quality of the saltpeter was low (for instance if it was contaminated with highly hygroscopic calcium nitrate), or if the powder was simply old (due to the mildly hygroscopic nature of potassium nitrate), in humid weather it would need to be redried. The dust from "repairing" powder in the field was a major hazard.

Loading cannon or bombards before the powdermaking advances of the Renaissance was a skilled art. Fine powder loaded haphazardly or too tightly would burn incompletely or too slowly. Typically, the breech-loading powder chamber in the rear of the piece was filled only about half full, the serpentine powder neither too compressed nor too loose, a wooden bung pounded in to seal the chamber from the barrel when assembled, and the projectile placed on that. A carefully determined empty space was necessary for the charge to burn effectively. When the cannon was fired through the touchhole, turbulence from the initial surface combustion caused the rest of the powder to be rapidly exposed to the flame.

The advent of much more powerful and easy to use corned powder changed this procedure, but serpentine was used with older guns into the seventeenth century.