Mr. James (_Military Dictionary_, p. 348) says, that it has been recommended to preserve gunpowder at sea by means of boxes lined with sheet-lead. M. D. Gentien, a naval officer, tried the experiment by lodging a quantity of gunpowder and parchment cartridges in a quarter of the ship which was sheathed in this manner. After they had been stowed for a considerable time, the gunpowder and cartridges were found to have suffered little from the moisture; whilst the same quantity, when lodged in wooden cases, became nearly half destroyed. It has been recommended to line powder magazines with lead, as a mean for preserving the powder from dampness. The lead, it seems, so far attracts moisture, as to condense it. In the last volume of the _Transactions of the American Philosophical Society_, is a memoir on _leaden_ cartridges, by Wm. Jones, Esq. the late secretary of the navy, which, besides preserving the powder, has advantages over either paper or flannel. See Magazine. What is termed the _analysis of gunpowder_, is nothing more than the separation of its component parts, and determining the relative proportions of its respective ingredients. We may indeed examine the quality of the nitrate of potassa, by dissolving a portion of powder in distilled water, and employing the reagents mentioned under the head of nitre; but for the purpose of separating, as well as determining the proportion of saline matter, charcoal and sulphur, it may be readily accomplished in the following manner: Take a given quantity of gunpowder and affuse it in distilled water sufficient to dissolve the salt; after suffering it to remain for some time, applying heat to assist the solution, decant the whole upon a filter of unsized paper. The saltpetre and other saline matter will pass through, and the sulphur and charcoal remain on the filter. By evaporating the solution to dryness, and weighing it, the quantity of saltpetre will be found; or, after drying the mass on the filter, and weighing it, by subtracting its weight from that of the original, it will give the loss sustained, which of course is the saltpetre. By exposing the mass to a heat sufficient to evaporate the sulphur, it will be expelled; the loss sustained will indicate its quantity, and the weight of the residue the proportion of charcoal. The sulphur may be even separated by subjecting gunpowder itself to the action of a well regulated heat; it will sublime, and leave the nitre and charcoal. It takes a much higher temperature to inflame gunpowder than is required to volatilize sulphur. The method of extracting the nitre from damaged powder, we have already noticed. See _nitre_. This process also depends on the solubility of the nitre, and the insolubility of the charcoal and sulphur. Bishop Watson, in his _Chemical Essays_, proposed the examination of gunpowder by solution and sublimation; a process sufficiently accurate. If it should be our object to ascertain the presence and quantity of foreign substances,