On the Absorption Spectrum of Benzene in the Ultraviolet Region

IN the Transactions of the Chemical Society for August Messrs. Baly and Collie, referring to the previous work of Baly and Desch (Trans. Chem. Soc., 1904, lxxxv., 1029, and 1905, lxxxvii., 766) on the absorption spectrum of acetylacetone and its derivatives and the conclusions arrived at, namely, that the absorption band is caused by dynamic isomerism, or rather isodynamic changes, are led to infer from the occurrence of bands in the spectrum of benzene that these also are caused by the making and breaking of the carbon bonds in the molecule of the substance. I have given a similar, but not identical, explanation of the cause of the bands in the spectra of uric acid, murexide, and the ureides, and have pointed out that there is but little difficulty in accepting a like explanation in order to account for the bands in aromatic hydrocarbons, seeing that this would harmonise with Kekule's view of the constitution of benzene. The particulars are contained in two papers communicated to the Chemical Society on May 17, but as they are still unpublished I cannot refer to them in detail.