Mr. Warington suggested that some HCl gas should be simultaneously passed with the nitrogen and hydrogen, and that the temperature of the spongy platinum should be kept just below the temperature at which NH_3 dissociates, in order to improve the yield of NH_3. _"On the Oxidation of Organic Matter in Water"_ by A. Downes. The author considers that the mere presence of oxygen in contact with the organic matter has but little oxidizing action unless lowly organisms, as bacteria, etc. be simultaneously present. Sunlight has apparently considerable effect in promoting the oxidation of organic matter. The author quotes the following experiment: A sample of river water was filtered through paper. It required per 10,000 parts 0.236 oxygen as permanganate. A second portion was placed in a flask plugged with cotton wool, and exposed to sunlight for a week; it then required 0.200. A third portion after a week, but excluded from light, required 0.231. A fourth was boiled for five minutes, plugged, and then exposed to sunlight for a week; required 0.198. In a second experiment with well water a similar result was obtained; more organic matter was oxidized when the organisms had been killed by the addition of sulphuric acid than when the original water was allowed to stand for an equal length of time. The author also discusses the statement made by Dr. Frankland that there is less ground for assuming that the organized and living matter of sewage is oxidized in a flow of twelve miles of a river than for assuming that dead organic matter is oxidized in a similar flow.--_Chem. News._ * * * * * ROSE OIL, OR OTTO OF ROSES. By CHARLES G. WARNFORD LOCK. This celebrated perfume is the volatile essential oil distilled from the flowers of some varieties of rose. The botany of roses appears to be in a transition and somewhat unsatisfactory state. Thus the otto-yielding rose is variously styled _Rosa damascena, R. sempervirens, R. moschata, R. gallica, R. centifolia, R. provincialis_. It is pretty generally agreed that the kind grown for its otto in Bulgaria in the damask rose (_R. damascena_), a variety induced by long cultivation, as it is not to be found wild. It forms a bush, usually three to four feet, but sometimes six feet high; its flowers are of moderate size, semi-double, and arranged several on a branch, though not in clusters or bunches. In color, they are mostly light-red; some few are white, and said to be less productive of otto.