This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
Source. - Obtained from American petroleum by distilling off the lighter portions and purifying the residue.
Characters. - A yellowish semi-solid fat-like mass, transparent, odourless, tasteless, neutral. Insoluble in water; freely soluble in fixed and volatile oils.
Vaseline cannot become rancid or irritant to the skin, and, being readily miscible with many active substances, such as the phenol compounds and alkaloids, is indicated as a valuable basis for ointments instead of lard. Its chief disadvantage is the low point at which it melts, and its consequent tendency to spread through the dressings. It is now extensively used.