The Provenance of Historical Gunpowder from South-Western Japan: A Stable Isotopic Approach

Stable isotopic analysis was undertaken for the gunpowder ingredients from crude saltpetre and propellants from several types of gun that prevailed during the late 19th century in south-western Japan. Stable isotopic signatures for δ¹⁵N_{saltpetre nitrogen}, δ³⁴S_{native sulphur} and δ¹³C_{charcoal carbon} in crude saltpetre, gunpowder magazines bearing the trademark of mills from southern Scotland and cartridges for an improved Sharps rifle (with a US trademark) all imply common assemblages from the same source (saltpetre and native sulphur from British India and Sicily, respectively) in the United Kingdom (UK). One Pritchett patron is common for muzzle-loading Enfield rifles, while the other suggests a four-allied lead bullet for an unidentified hand gun. Propellants in the Pritchett patron from the same institution also suggest a common source of these rifles. On the contrary, the ingredients for an unidentified rifle and time fuse for a Paixhans gun with unique stylistic devices showed distinctive isotopic signatures, indicating a local Japanese origin. The Pritchett patron from the Kumamoto Museum involved a mixed provenance from the UK and Japan. The stable isotopic analysis provides direct evidence for the ultimate origin of the propellant.