MURAKAMI and his collaborator had isolated the hepatitis virus from hepatitis patient and cultured in the chorio-allantoic cavity of chick embryo. The author newly isolated the hepatitis virus from the patient and studied on virological properties of the virus having obtained the purified virus. The following results were obtained. 1) In the treatment by heating or by disinfectant, the purified virus showed high resistance to these treatment, and these resistances were thought to be the featuring properties of the virus. 2) Also it was observed that the virus was highly resistant to irradiation of ultraviolet rays, and to action of ether. 3) The purified virus was highly infections to mouse by peroral administration of it. The pathological ...