"The waxed paper is laid in the solution, in a flat porcelain or gutta percha tray, in the manner described by M. Le Gray and others, and allowed to remain there for from half an hour to an hour, according to the thickness of the paper. It is then taken out and hung up to dry, when it should be of a light brown colour. All these operations may be carried on in a light room, taking care only that, during the latter part of the process, {94} the paper be not exposed to the direct rays of the sun. "The 'iodized paper,' which will keep for almost any length of time, should be placed in a portfolio, great care being taken to lay it perfectly flat, otherwise the wax is liable to crack, and thus spoil the beauty of the negative. The papers manufactured by Canson Frères and Lacroix are far preferable, for this process, to any of the English kinds, being much thinner and of a very even texture. "To render the paper sensitive, use the following solution: 150 grains nitrate of silver crystals. 3 fluid drachms glacial acetic acid, crystallizable. 5 ounces distilled water. "This solution is applied in the way described by Le Gray, the marked side of the paper being towards the exciting fluid. The paper is washed in distilled water and dried, as nearly as possible, between folds of bibulous paper. It should be kept, till required for the camera, in a portfolio, between sheets of stout blotting-paper, carefully protected from the slightest ray of light, and from the action of atmospheric air. If prepared with any degree of nicety, it will remain sensitive for two or three weeks: indeed I have seen some very beautiful results on paper which had been kept for a period of six weeks. At this time of year, an exposure in the camera of from ten to twenty minutes is requisite. "The picture may be developed with gallic acid, immediately after its removal from the camera; or, if more convenient, that part of the process may be delayed for several days. Whilst at this section of my paper, I may, perhaps, be allowed to describe a method of preparing the solution of gallic acid, whereby it may be kept, in a good state of preservation, for several months. I have kept it myself for four months, and have found it, after the lapse of that period, infinitely superior to the newly-made solution. This process has, I am informed, been alluded to in photographic circles; but not having seen it in print, and presuming the fact to be one of great practical importance, I trust I shall be excused for introducing it here, should it not possess that degree of novelty I attribute to it.