LAM circumstances which our limits will not permit us to discuss, as they relate peculiarly to surgery. A practical work on this subjeft is much wanted ; and we conceive it would be of essenlial service to society, if a popular treatise were properly executed, in which the manifold causes of lameness might be discriminated, and the most appropriate remedies judiciously stated, according to the diiierent stages of the atfedion. Lameness, in Horses. See Halting. LAMP, a vessel containing oil, or other inflammable matter, for the purpose of atfording light. The utility of lamps in domestic life, is universally acknowledged ; we shall, therefore, proceed to state such patents as have been granted for the inventions or improvements relative to this branch of manu- faCmre, without discussing those theories in which ingenious men have occasionally indulged. The first we shall notice is, that of M. Argand, who obtained a patent in 178-I : his privilege being now expired, and his invention generally adopted, we shall brielly observe, that the superiority of his lamp depends on the admission of a larger volume of air to the flame, than is practicable on the common plan. Ihis obie(!:f is elfected by employing a circular wick, so that a strong current of air rushes into the cylinder round which the wick i.^ placed, and thus, together with the atmosphere, excites the flame to such a degree, that tl-e smoke is entirely consumed. I'he light and heat are by this method re- markably increased, while the ex- pence of the oil is considerably re- duced j because those particles, which, in the usual lamps, are dis- LAM 16 1 sipated in smoke, will, by M. Ar- gand's invention, be converted into a brilliant flame. A patent was granted in 1 ysf (o Mr. Miles, for his new method of making lamps of ditferent forms, so as to emit an undiminished light, however it may be agitated ; "and which may also be fixed in halls, shops, &c. — Asitsspecificationistoo complex to be understood by those who are unacquainted with the ma- nufacture, inquisitive readers will consult the 3d vol. of the Repertory of Arts and MamifaBures. Another patent was obtained ia the same year, by Mr. Petek Keir, for a contrivance of raising the sup- ply of oil in lamps. The whole eifeCt is produced by the applica- tion of another fluid, the specific gravity of which is greater than that of oil; and which communicates with the latter, hy means of cer- tain receivers, tubes, or conduc- tors. These are so aiianged, that the heavier liquid may press a co- lumn of oil upwards to any reoui- site height, for the purpose of sup- plying the lamp. Farther, by prolonging th.e con- duftor of the heavier fluid beneath the lower surface of the column of oil, the weight of the former will hydrostatically aft upon such sur- face, and raise the column. Ihus, the lamp will not only be furnished with the purest partic es of oil fiora the upper part, but the flame will also be considerably elevated above the body of the vessel ; and, being supplied from a contracted surface of oil, it will consequently attord a more difl'used light, with a con- siderable diminution of shade. For a more minute account of this inge- nious contrivance, we refer the in- quisitive reader to the Sth vol. of the work before quoted. The
