A research group consisting of Dr. Masataka Aizawa, Professor of the Graduate School of Science and Engineering, Ryukyu University, Professor Emeritus Tomotoshi Mizoda of Iwate University, Professor Takahiro Hosono of the Graduate School of Advanced Sciences, Kumamoto University, and Professor Ryuichi Shinshiro of the Institute of Global Environmental Studies Examination of the lead of the bullets used during the period from the end of the Edo period to the Meiji Restoration revealed that about half came from the United Kingdom.
According to Ryukyu University, the research group collected bullets used in the end of the Edo period, the Yang Earth Dragon, and the Satsuma Rebellion from all over Japan, and measured the lead isotope ratio (* 1).We compared it with the isotope ratios of lead produced in major mines in Western countries.As a result, half of the lead used at that time was produced in Japan, but the other half had the same isotope ratio as that produced in the United Kingdom.
At that time, Western countries were expanding into various parts of the world and competing for colonies.Britain was in control as wars using firearms such as the Napoleonic Wars and the American Civil War and civil wars continued in various parts of the country.Since British lead was also used in the bullets used during the isolation period when Japan traded only with the Netherlands and China, British lead was widely distributed around the world. It became clear.
It is known that the lead of the ammunition used in Japan during the Warring States period was produced not only in Japan but also in China, Thailand and the Korean Peninsula.It has been proved that the distribution of lead resources has changed significantly in about 300 years due to the global expansion of Western countries.
* 1 Lead isotope ratio The ratio of four isotopes contained in lead.Numerical values vary by region and are used to estimate the origin of archaeological relics
