=Seignior Carlos Relvas.=—Vidal publishes the following method of procedure as that adopted in the studio of this eminent Portuguese amateur collotypist, where it was introduced by Jacobi:—Very thick glass plates, finely ground on one side, are used; they are cleaned with nitric acid, and rinsed in distilled water. The drying box used is provided with iron bars, fitted with adjustable screws for the purpose of accurately levelling the plates. Midway between the top and bottom of the box is an iron plate, underneath which are fitted gas jets. The doors by which access to the box is gained for the plates consists of very fine wire gauze, allowing the escape of steam, but preventing the access of insects. After a thorough cleansing, the plates are levelled on the adjusting screws, allowed to thoroughly dry, and then coated on the ground side with the following solution— White of egg 160 ccm. Bichromate of potassium 8 g. Distilled water 480 ccm. Glycerine 16 drops. To which is added sufficient ammonia to give the liquid a pale yellow tint, somewhat less being used where a hard negative is to be employed. This substratum is filtered, and the plates afterwards coated and placed upon the levelling screws in the drying box, which is heated to a regular temperature of 40° C. In about two hours the plates will be dry, and are then placed, coated side downwards, upon a black cloth, the back of the plate being exposed to diffused light for half-an-hour. It is again placed in the drying box, and the second coating, as follows, applied— Gelatine 27 g. Water 400 ccm. Bichromate of potassium 9 g. Preparation A 15 ccm. Preparation B 15 ccm. Ammonia a few drops. The preparations A and B are as follow: A.—Chloride of sodium 1 g. Water 500 ccm. B.—Sulphate of alumina 1 g. Water 100 ccm. To each square decimetre of surface should be allowed 2 ccm. of the above solution. The plates are replaced in the drying box, which is heated to 45° or 50° C. They should be dry in three hours, and are then ready for printing under a negative in the copying frame. They are afterwards well washed in filtered water, and allowed to dry spontaneously in a dust-proof situation. In two or three days the printing may be proceeded with, the surface having been softened by allowing the plate to stand for seven hours in the following solution— Glycerine 500 ccm. Distilled water 200 ccm. Preparation C 100 ccm. PREPARATION C.—Sulphate of magnesia 50 g. Distilled water 500 ccm.