Koichi Ichikawa

Pathologist and animal husbandry scientist. Born in Ibaraki Prefecture. Graduated from the Department of Animal Husbandry at Tohoku Imperial University College of Agriculture (formerly Sapporo Agricultural College, the predecessor to Hokkaido University's Faculty of Agriculture) in 1913 (Taisho 2). Became an experimental assistant to Professor Yamagiwa Katsusaburo at the Department of Pathology, Faculty of Medicine, Tokyo Imperial University, where he was involved in carcinogenesis experiments in which tar was repeatedly applied to rabbit ears. After observing the entire process for 200-500 days, he finally succeeded in artificially creating skin cancer for the first time in the world, and published the first report jointly by Yamagiwa and Ichikawa in 1915 (Taisho 4). For this research, he and Yamagiwa were awarded the Imperial Academy Prize in 1919. In 1925, he became a professor at Hokkaido Imperial University's Faculty of Agriculture, where he established a comparative pathology course in the Department of Animal Husbandry, and made many achievements in the field of animal pathology. Around the time of his successful cancer-inducing experiment, Ichikawa, who wrote the pen name "Hokkyoku," wrote a song that went, "Even though a hermit living on thirty-five yen's worth of food, all that he sees in the mirror is beauty," but the "thirty-five yen" he mentioned referred to him studying hard and borrowing 15 yen a month.

[Honda Kazuji]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

病理学者、畜産学者。茨城県生まれ。1913年（大正2）東北帝国大学農科大学（札幌農学校を改称、北海道大学農学部の前身）畜産科を卒業。東京帝国大学医学部病理学教室で山極勝三郎(やまぎわかつさぶろう)教授の実験助手となり、ウサギの耳にコールタールを反復して塗る発癌(はつがん)実験に従事した。200～500日間全経過を観察、ついに世界で初めて人工的に皮膚癌をつくることに成功し、1915年（大正4）山極・市川の連名で第一報を公表した。この研究で1919年、山極とともに帝国学士院賞を受賞。1925年北海道帝国大学農学部教授となり畜産学科に比較病理学講座を創設、家畜病理学について多くの業績をあげた。発癌実験に成功したころ「北極」と号した市川は「世捨人三五の糧(かて)に生くるとも鏡下に見ゆるものは錦繍(きんしゅう)」と歌ったが、「三五の糧」とは、月に15円の借金をして苦学していたからである。

［本田一二］

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