| ||Format||Pages||Price|| |
|PDF (136K)||10||$25||  ADD TO CART|
|Complete Source PDF (2.0M)||155||$55||  ADD TO CART|
Natural resins are solid or semi-solid materials of vegetable origin, being, in general, the hardened sap of trees. They are insoluble in water, but soluble in ether, alcohol and other solvents. They have no definite chemical composition, but contain complex bodies in varying amounts. This is especially true of the harder types. They contain carbon, hydrogen, and a small percentage of oxygen. Possessing no definite melting points, they fuse gradually, often undergoing partial decomposition during the heating process.
The Resinous Products and Chemical Co., Philadelphia, Pa.