C.P. Thunberg Introduced Western Medicine and Pharmaceutical Science into Japan in the 18th Century

Abstract

C.P. Thunberg, a Swedish medical doctor and botanist who arrived in Japan in 1775, is the author of Flora Japonica, which is highly acclaimed for introducing modernized floristics to Japan. As a medical doctor, he reportedly introduced mercury therapy for syphilis to Japan, but the circumstances have been unclear. This paper focuses on Thunberg as a medical doctor as well as Uppsala University School of Medicine,Sweden, where Thunberg learned medicine, and three medical papers he wrote before his trip to Japan in order to demonstrate that he possessed the most advanced medical knowledge of his time. We reviewed Komohijiki written by Kogyu Yoshio, one of the Japanese-Dutch interpreters who learned about mercury water from Thunberg, and books written by van Swieten, an Austrian doctor who clinically evaluated mercury water, and concluded that the mercury water introduced by Thunberg was a 0.1% solution of mercuric chloride, which was later named van Swieten water and included in Western pharmacopoeias from the 1830 s through the 1930 s. In Japan, nearly half a century was needed after the introduction of mercury water before books on Western medicines that introduced correct information were published. The highest dose of mercuric chloride established by van Swieten was retained in the Japanese Pharmacopoeia up to its 5th edition. Thunberg should be regarded highly not only as a botanist but as a medical doctor as well.