At present, vanillin is prepared artificially. Tiemann and Harmann first showed that by the oxidation of coniferin, a glucoside occurring in the cambial sap of the _Coniferæ_, a product, perfectly identical with the vanillin prepared from vanilla, is obtained. The coniferin is obtained by barking the pine or silver fir, scraping together the sap under the bark together with a portion of the liber and pouring it into a vessel. The sap is then pressed off, boiled to separate the albumin, filtered, evaporated to one-fifth its volume, and set aside to crystallize. One hundred quarts of sap are said to yield from 1 to 2 pounds of coniferin-crystals. By now allowing an aqueous coniferin-solution to run into a heated mixture of 10 parts potassium bichromate, 15 parts concentrated sulphuric acid, and 80 parts water, and heating for 3 hours in a flask with back-flow cooler, a liquid is obtained from which ether takes up a yellow oil. After treating the latter with animal charcoal, dissolving in ether and evaporating the latter, there remain colorless, acicular crystals of the odor and taste of vanilla. These crystals consist of vanillin contaminated with some vanillic acid. To separate the latter, purify with acid sodium sulphite and recrystallize. After this operation, vanillin represents a nearly white crystalline powder which melts at from 176° to 177.8° F. In this form it is brought into commerce as a complete substitute for vanilla, 5.64 drachms of it corresponding to about 1 pound of vanilla. A medium-sized pine tree is said to yield vanillin of the value of 80 marks ($19.20). Vanillin may also be prepared by oxidation from eugenol. Oil of cloves is diluted with three times its volume of ether and agitated with weak caustic potash solution to fix the eugenol on the potash. By acidulating the alkaline solution and shaking with ether, the eugenol is collected. After distilling off the ether, the eugenol is converted with acetic anhydride into aceteugol, and the latter oxidized with dilute, moderately-warmed potassium permanganate solution. The filtrate is made slightly alkaline, concentrated, then compounded with acid and the vanillin extracted with ether. Vanillin (C_{8}H_{8}O_{3}) forms small colorless prisms of a strong vanilla odor, a warm, vanilla taste, and an acid reaction. It is readily soluble in hot water, alcohol, ether, chloroform, fat and volatile oils, as well as in solutions of caustic alkalies and alkaline carbonates. It melts when heated to from 176° to 177.8° F.; at a higher temperature it sublimates without leaving a residue.