From a chemical point of view cananga oil has become interesting because of the information given by Gal,[1] that it contains benzoic acid, no doubt in the form of a compound ether. So far as I, at the moment, remember the literature of the essential oils, this occurrence of benzoic acid in plants stands alone,[2] although in itself it is not surprising, and probably the same compound will yet be frequently detected in the vegetable kingdom. As it was convenient to test the above statement by an examination I induced Herr Adolf Convert, a pharmaceutical student from Frankfort-On-Main, to undertake an investigation of ilang-ilang oil in that direction. The oil did not change litmus paper moistened with alcohol. A small portion distilled at 170° C.; but the thermometer rose gradually to 290°, and at a still higher temperature decomposition commenced. That the portions passing over below 290° had a strong acid reaction already indicated the presence of ethers. Herr Convert boiled 10 grammes of the oil with 20 grammes of alcohol and 1 gramme of potash during one day in a retort provided with a return condenser. Finally the alcohol was separated by distillation, the residue supersaturated with dilute sulphuric acid, and together with much water submitted to distillation until the distillate had scarcely an acid reaction. The liquid that had passed over was neutralized with barium carbonate, and the filtrate concentrated, when it yielded crystals, which were recognized as nearly pure acetate. The acid residue, which contained the potassium sulphate, was shaken with ether; after the evaporation of the ether there remained a crystalline mass having an acid reaction which was colored violet with ferric chloride. This reaction, which probably may be ascribed to the account of a phenol, was absent after the recrystallization of the crystalline mass from boiling water. The aqueous solution of the purified crystalline scales then gave with ferric chloride only a small flesh-colored precipitate. The crystals melted at 120° C. In order to demonstrate the presence of benzoic acid Herr Convert boiled the crystals with water and silver oxide and dried the scales that separated from the cooling filtrate over sulphuric acid. 0.0312 gramme gave upon combustion 0.0147 gramme of silver, or 47.1 per cent. The benzoate of silver contains 46.6 per cent, of metal; the crystals prepared from the acid of ilang-ilang oil were, therefore, benzoate of silver. For the separation of the alcoholic constituent, which is present in the form of an apparently not very considerable quantity of benzoic ether, far more ilang-ilang oil would be required than was at command. [Footnote 1: _Comptes Rendus_, lxxvi. (1873), 1428, and abstracted in the _Pharmaceutical Journal_ [3], iv., p. 28; also in _Jahresbericht_, 1873, p. 431.] [Footnote 2: Overlooking Peru balsam and Tolu balsam.]