We see, by nearly all of our English cotem-poraries devoted to science and inventions, that they speak in high terms of the discovery of a Dr. Watson, whereby the electric light is rendered perfectly successful and economical, and by which, also, electro-magnetism will be economically applied to drive machinery and supersede steam. The whole o) the economy of the new discovery of Dr. Watson lies in making useful products out of the materials employed to generate the electricity. At the present moment, for example, the sulphate of zinc is the product of employingzinc and sulphuric acid in the battery. Dr. Watson is going to employ lead as the metal, and the bichromate ot potash as a fluid in the battery, which will produce the chromate ol lead, a beautiful yellow pigment employed by painters. A company named the " Electric Power and Color Company," has been formed in London with a large capital, and a great establishment is to be erected in a short time ,to carry out the project. We have no hope of the electric light or electro-motive power being so economical, for light on the one hand, or motive power on the other, as to supersede present modes of lighting, or the steam engine. The Electric Light is stated to be very splendid, not requiring air for burning, and that it will burn under water. The qualities which the light are said to possess, are no greater than those which our English friends spoke so highly of, as belonging to Staite's Electric Light, a few years ago, and which utterly failed, because of its great expense. We know that the useful materials—the chromate of lead—said to be produced by Dr. Watson's process, cannwt make his plan so economical as to compete with gas light, or generate a power to com pete with steam.