The substance which is the subject of investigation in this paper is a volatile oil, obtained by distillation from a mixture of bran, sulphuric acid and water, and is designated by the author by the name of furfurol . Its chemical composition is expressed by the formula C 15 H 6 O 6 , and its properties are the following:—When free from water and freshly rectified, it is nearly colourless; but after a few hours, it acquires a brownish tint, which eventually deepens almost to blackness. When in contact with water, or when not properly rendered anhydrous, it is less subject to change, and merely assumes a yellow colour. Its odour resembles that of a mixture of bitter almond oil and oil of cassia, but has less fragrance. Its specific gravity at 60° Fahr. is 1·168; it boils at 323° Fahr., and distils at that temperature without alteration. It dissolves to a large extent in cold water and also in alcohol. Its solution in concentrated sulphuric acid has a magnificent purple colour, and is decomposed by water. Nitric acid, with the aid of heat, attacks the oil with prodigious violence, evolving copious red fumes, and generating oxalic acid, which appears to be the only product. It dissolves in a solution of caustic potash, forming a deep brown liquid, from which acids precipitate a resinous matter. With a slight heat, it explodes when acted upon by metallic potassium. When placed in contact with 5 or 6 times its bulk of Liquor ammoniæ , it is gradually converted into a solid, yellowish-white, and somewhat crystalline mass, which is very bulky, perfectly soluble in cold water, and easily obtained in a state of dryness under a vacuum. The formula expressing the chemical constitution of this substance, or of furfuroamide , as the author calls it, is C 15 H 6 N O 3 , and it is classed by him with the amides . The oil itself appears to be identical with the substance described by Dr. Stenhouse under the name of artificial oil of ants . Another substance, isomeric with the amides, and of which the formula is C 30 H 12 N 2 O 6 , was obtained by the author, and termed by him furfurine ,and found to have the properties of a vegeto-alkali, and to form saline compounds with various acids.