The stable isotopic composition of historical black powder applicable to a Japanese Tanegashima matchlock

The objective of the present study is to employ stable isotope ratio measurements (δ¹⁵N, δ³⁴S and δ¹³C) of the nitrogen, sulphur and carbon in black powder (a mixture of saltpetre, native sulphur and charcoal) as a means of source identification. A sum total of 20 samples of historical black powder applicable to matchlocks were collected from six locations throughout Japan. This classic type of hand gun prevailed up to the introduction of the modern rifles, with quicker loading and higher efficiency, in the mid-to-late 19th century. δ¹³C_{charcoal carbon} values showed the predominant use of C₃ plants as a source material. Except for a few unusual samples with a probable exotic origin, δ¹⁵N_{saltpetre nitrogen} values were largely consistent with those of domestic products using classical biotechnology. The isotopic analysis for native sulphur (δ³⁴S_{native sulphur}) indicates a complicated marketing route.