1. Crystalline barium salt of heparin was prepared from ox lung according to Charles and Scott.
2. Hexuronic acid contained was identified with glucuronic acid.
3. Glucuronic acid was present in the equivalent proportion to glucosamine of 1 to 1, as in mucoitin.
4. None of the amino group of glucosamine was free, but it is not considered as acetylated, contrary to the case in mucoitin obtainable from vitreus humor, umbilical cords and other sources.
5. Our heparin barium salt contained 1.84 equivalents of sulphur when expressed as sulfomonoester.
The expenses of this work were defrayed by the Toshogu Tercentenary Memorial Endowment, which is gratefully acknowledged.