Edmund Naumann, a geologist employed by the Japanese government in the early Meiji period, visited Shikoku Island for geological investigation in 1883. At that time, two medical doctors named Otsuka and Teshima asked him to judge the quality of coal in the Ryoseki area of Kochi Prefecture. Little was known about Teshima until after a recent discovery of his grave and the remains of his house, which was used as a hospital and a private school in and around Ryoseki . He is identified Yoshinaga and was 53 years old at the time.