From the officinal guaiac resin from Guaiacum officinale, L, (family Zygophyllaceae) O. Doebner and H. Lucker1) obtained 0,66 p.c. of an volatile oil which gradually became solid.

By distilling the resin with high-tension steam, H. Haensel2) obtained but 0,03 p.c. of a dark brown, aromatic oil which was not completely soluble in 96 p.c. alcohol and which possessed the following properties: d15o0,9417; A. V. 77; E.V.I 2,8; when heated with ammoniacal silver solution it yielded a mirror.

According to E. Pastzold3) the oil is neither a constituent of the wood nor of the resin, but of the bark with which the resin is mostly contaminated.