Commercial Tolu balsam is frequently more or less mixed with vegetable remains, which, however, can be readily detected with the microscope, especially after the solution of the resinous constituents. It is frequently adulterated with turpentine or pine resin. Such adulterations may be detected by bisulphide of carbon, which completely dissolves these substances, but not the Tolu balsam. When pure Tolu balsam is triturated with concentrated sulphuric acid, a cherry-red fluid is, according to Ulex, obtained, which does not evolve sulphurous acid, as is the case in the presence of turpentine-resins.
Tolu balsam is chiefly used for fumigating pastilles. The tincture prepared from it is also frequently used with advantage to give durability to the scent of handkerchief perfumes.
According to Holmes and Nalor, a Tolu balsam differing in its chemical behavior is found in the English wholesale trade. In thick layers it is yellow-brown, but perfectly transparent and gold-yellow in thin layers and extraordinarily sticky. By storage it hardens but slightly, and does not become brittle even if exposed for several days to a temperature of 212° F. Its odor reminds one somewhat of glue, and it develops a pungent, sharp taste only after chewing it for a few seconds. Its melting point lies at 136.4° F., being lower than that of ordinary Tolu balsam, from which it also differs in that it completely dissolves in ether as well as in benzine, while it is only partially dissolved by potash lye. The balsam contains no toluene, nor a hydrocarbon, boiling at 320° F. Further investigations have shown it actually to be a natural product, the derivation of which, however, could not be ascertained.
_Storax_ is the produce of _Liquid ambar orientale, Mill_, a plantain-like tree which reaches a height of about 32 feet. In Southern Asia Minor, especially in Cyprus, the tree forms handsome, dense forests. According to Flückiger, the balsam is extracted from the peeled-off bark, with the assistance of warm water. The mass thus melted out sinks down in the water, and is later on combined with the substance obtained by expressing the boiled bark while still warm. This mixture forms the _liquid storax_ (_Storax liquidus_). The residue remaining after expression is dried in the sun and forms, under the name of _Cortex thymiamatis_, an article of commerce, which is used for fumigating purpose, for the preparation of ordinary storax, etc. The crude storax is brought to Smyrna, Syra, and Kos, and comes into the European market almost exclusively from Trieste.