vascular tissue

4381 Chem.: Petroleum jelly. A pale yellow, translucent, semi-solid substance, consisting of a mixture of the hydrocarbons C16H34 and C20H49, obtained by treating the undistilled portion of petroleum with superheated steam, and filtering while hot through animal charcoal. It is insoluble in water, very slightly soluble in alcohol, but di olves freely in ether, chloroform, benzine, and turpentine, is miscible in all proportions with fixed and volatile oils, melts at 35°-40°, and commences to fume at 160°. Its density in the melted state is '840-866. Pure vaseline does not turn rancid on exposure to the air, a property which renders it a valuable substitute for lard, ., in the preparation of ointments liable to change. It is also said to po e curative powers [VASCULAR-SYSTEM, 1.]