Specification of the Patent granted to JOHN WILLIAMS, of Cornhill, in the City of London, Stationer; for a new Mode of covering and inclosing all Kinds of Carriages.

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Dated December 9, 1807.

any

To all to whom these presents shall come, &c. Now KNOW YE, that in compliance with the said proviso, I the said John Williams do hereby declare that the nature of my said invention, and the manner in which the same is to be performed, are particularly described and ascertained as follows; that is to say; I construct a moveable frame or cover, capable of being disposed between grooves or within a cell or space in the body of the carriage, and of being drawn up by one or more straps or webs, suitably disposed, so as to act nearly in the manner commonly adopted with regard to the glasses or blinds of carriages; and I do accordingly dispose and fit up the said frame or cover in the method here mentioned and described. And I do make the said frame or cover of fit and proper materials, and put or make therein windows or apertures when or if required; and when the materials thereof are inflexible, I do make the same of such a form or figure as shall be capable of mathematical description about a real or imaginary axis; that is to say; I do make the said form or figure spherical, spheroidal, cylindrical, or of such other description as shall in its own nature have reference to an axis. And I do make my carriage, or the grooves, spaces, or other receptacles therein, and into what the said frame or cover shall be intended to slide, of a correspondent figure, adapted to the purposes hereinbefore mentioned. And farther, I do make the said frame or cover of any desired magnitude, with ends or sides, or in such other manner as shall cover either part or the whole of the carriage in such places where the same would otherwise

have

have remained open and uncovered; and I do by stops, pins, or holes in the straps or webs hereinbefore mentioned, or by other fit and obvious methods and contrivances, provide that the said frame or cover shall and may be drawn out of the said grooves, spaces or receptacles, in greater or less degrees or quantity as may be needful, and fixed in the positions so obtained. And farther, in other cases in the practice of my said invention, instead of making my cover of inflexible materials, I do make the same of small rods, bars, or pieces of wood or metal, and joined sideways together, either by tying, or sewing or glewing the same to a cloth, or otherwise to. each other, as hath been done in the covers of writing-tables, and some other articles. And in this method of structure it is not necessary that the grooves, cells, spaces or receptacles in the carriage should have a figure referable to an axis as aforesaid; because the said cover may evidently be disposed in various different kinds of receptacles, which it is unnecessary to describe, because sufficiently obvious to every competent workman. And farther, I do, in other cases, make my said cover of cloth or other flexible material; and, in this last mentioned construction the disposal of the same in the body of the carriage, and the use and management of the same, will require and admit of other variations, which are also suffi ciently manifest. And in every case wherein the said cover is or shall be made of materials more or less flexible, it will be needful that certain leaders or supports should be provided and made, in order that the same may be held and secured in its place when in use. And, lastly, I do declare that my said invention is applicable to all kinds of carriages or vehicles for conveyance, either by land or by water; and that the same may be made in various elegant forms of slighter or stronger materials, as may be required, and that in its own nature is very durable.

In witness whereof, &c. ..

On

On some Chemical Agencies of Electricity.

By HUMPHRY DAVY, Esq. F. R. S. M. R. I. A.

(Concluded from Page 204.)

V. On the Passage of Acids, Alkalies, and other ́Substances, through various attracting Chemical Menstrua, by means of Electricity.

As acid and alkaline substances, during the time of their electrical transfer, passed through water containing vegetable colours without affecting them, or apparently combining with them, it immediately became an object of inquiry, whether they would not likewise pass through chemical menstrua having stronger attractions for them; and it seemed reasonable to suppose that the same power which destroyed elective affinity in the vicinity of the metallic points, would likewise destroy it, or suspend its operation, throughout the whole of the circuit.

An arrangement was made of the same vessels and apparatus employed in the experiment on the solution of muriate of soda and sulphate of silver, page 204. Solution of sulphate of potash was placed in contact with the negatively electrified point, pure water was placed in contact with the positively electrified point, and a weak solution of ammonia was made the middle link of the conducting chain; so that no sulphuric acid could pass to the positive point in the distilled water without passing through the solution of am

monia.

The power of 150 was used: in less than five minutes it was found, by means of litmus paper, that acid was collecting round the positive point; in half an hour the result was sufficiently distinct for accurate examination.

VOL. XII.-SECOND SERIES.

LI

The

The water was sour to the taste, and precipitated solution of nitrate of barytes.

Similar experiments were made with solution of lime, and weak solutions of potash and soda, and the results were analogous. With strong solutions of potash and soda a much longer time was required for the exhibition of the acid; but even with the most saturated alkaline lixivium it always appeared in a certain period.

Muriatic acid from muriate of soda, and nitric acid from nitrate of potash, were transmitted through concentrated alkaline menstrua under similar circumstances.

When distilled water was placed in the negative part of the circuit, and a solution of sulphuric, muriatic, or nitric acid in the middle, and any neutral salt with a base of lime, i soda, potash, ammonia, or magnesia, in the positive part, the alkaline matter was transmitted through the acid matter to the negative surface, with similar circumstances to those occurring during the passage of the acid through the alkaline menstrua; and the less concentrated the solution, the greater seemed to be the facility of transmission.

I tried in this way muriate of lime with sulphuric acid, nitrate of potash with muriatic acid, sulphate of soda with muriatic acid, and muriate of magnesia with sulphuric acid; I employed the power of 150; and in less than 48 hours I gained in all these cases decided results; and magnesia came over like the rest.

Strontites and barytes passed, like the other alkaline substances, readily through muriatic and nitric acids; and, vice versâ, these acids passed with facility through aqueous solutions of barytes and strontites: but in experiments in which it was attempted to pass sulphuric acid through the same menstrua, or to pass barytes or strontites through this acid, the results were very different,

When

When solution of sulphate of potash was in the negative part of the circuit, distilled water in the positive part, and saturated solution of barytes in the middle, no sensible quan tity of sulphuric acid existed in the distilled water after thirty hours, the power of 150 being used; after four days, sulphuric acid appeared, but the quantity was extremely minute: much sulphate of barytes had formed in the intermediate vessel; the solution of barytes was so weak as barely to tinge litmus; and a thick film of carbonate of barytes had formed on the surface of the fluid. With solution of strontites the result was very analogous, but the sulphuric acid was sensible in three days.

When solution of muriate of barytes was made positive by the power of 150, concentrated sulphuric acid intermédiate, and distilled water negative, no barytes appeared in the distilled water when the experiment had been carried on. for four days; but much oxymuriatic acid had formed in the positive vessel, and much sulphate of barytes had been de posited in the sulphuric acid.

Such of the metallic oxyds as were made subjects of experiment passed through acid solutions from the positive to the negative side, but the effect was much longer in taking place than in the instances of the transition of alkaline matter. When solution of green sulphate of iron was made positive, solution of muriatic acid intermediate, and water negative, in the usual arrangement, green oxyd of iron began to appear in about ten hours upon the negative connecting amianthus, and in three days a considerable portion had been deposited in the tube. Analogous results were obtained with sulphate of copper, nitrate of lead, and nitromuriate of tin.

I made several experiments on the transition of alkaline and acid matter through different neutrosaline solutions, and the results were such as might well have been anticipated.