Professor Vogel has lately brought forward the curious fact that the generation of alkaloids in plants is dependent upon sunlight. The hemlock plant which yields coniine in Southern Europe contains none in Scotland. Again, the tropical cinchonas, from which quinine is obtained, will yield very little of that valuable product if cultivated in our weakly lighted hothouses. Professor Vogel has examined many specimens of the plant from various conservatories, and has been quite unable to obtain the characteristic reaction of quinine, although the method of testing is a delicate one, and sensitive to minute quantities of the alkaloid. It is curious to observe that although sunlight seems so necessary to the formation of quinine in the living plant, it acts most injuriously upon the alkaloid in the stripped bark. In the latter case, the quinine is decomposed by it, and assumes the form of a dark-coloured resin. Because of this, in the manufacture of quinine, the bark is always dried in the dark. The recent severe weather must have led many a half-frozen traveller to wonder if our railway and tramway Companies will ever hit upon some method of heating public conveyances. With a steam-engine as a necessary adjunct, it would seem to the disinterested inquirer that a method of warming by pipes fed from the ‘exhaust’ would be a comparatively easy way of managing the business, and would at the same time save much labour in doing away with the filling and distribution of inefficient foot-warmers. In Chicago, a new method of heating tramcars is being tried, and it promises well. The apparatus, which is placed under the floor of the car, consists of a brass cylinder filled with coal-oil, which, under pressure of a strong spring, is forced into a small super-heater, where it becomes vaporised. This oil-gas is ignited in a fire-clay combustion chamber, and although there is no flame, the fire-clay is brought to a white heat. The outer air passing over this hot box becomes well warmed, and a constant stream of fresh, warm air is assured to the passengers. The only visible evidence of the stove is a grating in the floor of the car through which the hot air rises. When will our tramway Companies consent to a small reduction in their high dividends, to afford their patrons similar comfort?