A team of researchers has just completed a series of tests of some medieval-era gunpowder recipes. Ostensibly in the name of science, this research was intended to understand the intent of master gunners when creating particular recipes of black powder. And it was not done for the pure hell of it, honest.
Gunpowder, otherwise known as black powder, is first recorded as being used in anger around 900AD in China. Shortly after, knowledge of the stuff spread throughout Eurasia, finally becoming a common appearance in 13th century Europe.
Largely obsolete today (it was replaced by things like cordite in the 1800s), it is still used today in things like fireworks, pyrotechnics, and some historical firearms.
Its introduction to Europe resulted in a literal explosion in gunpowder-based weapons of war from artillery to very early firearms. During this period, the formula for gunpowder was experimented with and tinkered with by specially skilled tradesmen called master gunners to make it more potent and safe to use.
It is exactly these recipes that researchers decided to forensically analyze by recording the relative amount of energy each recipe released during combustion. By doing this, it was hoped, that the researchers could track the trial-and-error process of gunpowder evolution over time.
Gunpowder, in case you are not aware, is a combination of specific ratios of potassium nitrate (or “saltpeter”), sulfur, and charcoal. During the middle ages, master gunners would also blend in other additives like camphor, varnish, or brandy, with obscure purposes.
To this end, Dawn Riegner, Cliff Rogers, and their team of chemists and historians wanted to analyze the energetics of medieval gunpowder recipes to help understand the intent of master gunners in creating these formulas. It was also hoped that the information gathered would be able to provide important technical information about early gunpowder manufacturing.
Blowing up stuff for science
Reigner, Rogers, and their team identified over 20 different gunpowder recipes from surviving medieval texts dating between 1336 to 1449 AD. Using these historical blends of black powder, the researchers created them faithfully to the original instructions.
Each concoction was then measured to assess its energetic contents just before and during combustion using differential scanning calorimetry and bomb calorimetry. The team also tested a few of the recipes at a West Point firing range using a replica of an early 15th-century stone-throwing cannon.
It would be rude not to, after all.
So, what were the results? The team's analysis of different types of gunpowder from the period showed that between 1338 and 1400 AD, the relative percentage of saltpeter increased, while charcoal decreased.
This resulted in lower heat of combustion of the powder, which would make them safer to handle for gunners of the period. After about 1400 AD, the relative content of saltpeter (which also happens to be the most expensive component), began to gradually decrease.
Sulfur and charcoal contents increased, which resulted in the powders increasing in combustion heat, though not as much as earlier recipes.
Other seemingly odd additives, like camphor and ammonium chloride, appear to have been added to make gunpowder stronger. However, others, such as water or brandy, did not show energetic advantages but might have served other purposes.
For example. the team theorizes it may have made the gunpowder more stable for transport or long-term storage.
However, these theories, as the research team admit, will require some fieldwork on firing ranges, rather than lab analysis, to test them properly.
How convenient? You can view the original research paper at the American Chemical Society (ACS).