THE ELECTRIC LIGHT.

The specification of this patent is at length finished; and a careful perusalof the document affords matter for grave consideration, as, unfortunately, it is but a sample of the numerous specifications of absolute impossibilities which we are afraid too frequently exist amongst the parchments of the Enrolment-office.

In our Former notices of the Electric Light, we showed that success or failure would depend upon the cost of the production of the voltaic power; therefore, we shall confine our attention to those parts of the specification which appertain to its economic production.

" To economise the products, when zinc is employed, I add (says the patentee), in a separate vessel, to the solution of sulphate of zinc a solution of sesquicarbonate of ammonia, which precipitates the oxide of the zinc metal, and releases the acid, which may be used again." Our readers, doubtless, will think that there is some mistake in this paragraph; that it is either misquoted or mis-printed, but we regret to state that it actually exists in the patent. We need hardly state, that every schoolboy, where chemistry is taught, knows that it would be impracticable to set free sulphuric acid by such means.

Again, the patentee speaks of using platinised plates of lead, or other metal, as the source of power. Now, the effect of adding platinum to the lead, or other metal, would be to increase local action, which would not in any manner contribute to the general power of the battery. Lead, moreover, as a positive pole, gives rise to a current of but very feeble intensity, and one, perhaps, quite inapplicable for the evolution of light.

In the specification, a considerable space is dedicated to the description of a perfluent battery, where the exciting fluid passes from cell to cell. This arrangemcnt is, perhaps, the very worst which could possibly be adopted by the electrician for a compound battery, as every cell would possess a fluid of different exciting power; and the terminal cells, if his intentions were carried out, would become precipitating troughs instead of battery cells-a state which the electrician always carefully prevents.

For the generation of voltaic power, or its economic production, we regret to state that there is not one single addition to our stock of knowledge; but throughout, the patent contains statements in direct violation of elactrical and chemical laws. All hope of an extensive application of the Electric Light must now be abandoned; but still we shall rejoice if it can be employed as a special mode of illumination on great public occasions.