Petrography
the art of writing on stone. Also the study of rocks; a scientific description of or treatise on rocks; that branch of geology which deals with the constitution of rocks; petrology.
PETROLATUM. Vaseline, petroleum jelly. A pale yellow to amber colored , oily, translucent, semi-solid substance, obtained by purifying the residue from the distillation of petroleum. Soluble in all common oil solvents, slightly soluble in alcohol, insoluble in water. Used in medicine, in the manufacture of shoe and metal polishes, and as a lubricant.
Liquid Petrolatum is a colorless, oily liquid, obtained from petrolatum, and consists of the fraction distilling between 330° and 390° C. It is chiefly used in medicine as an emollient.