Whatman's drawing or water-color paper is a very pure paper, and may be sensitized and used for photographic prints. The process is quite simple. Dissolve 75 grains of chloride of ammonium in 1 quart of water, filter through cotton or filtering-paper, and soak the paper in this solution for three minutes, or until it is thoroughly saturated; then lay it on a clean flat surface to dry, using care in handling so as to avoid stretching or tearing. This process is called "salting the paper." The sensitizing solution is prepared as follows: Dissolve 3/4 oz. of nitrate of silver in 8 oz. of water. Take two-thirds of this solution, and precipitate the silver by adding strong ammonia water drop by drop. This will cause the solution to turn brown. Continue adding the ammonia till this brown precipitate is dissolved and the solution becomes clear again. As soon as it clears, turn in the rest of the silver solution which contains no ammonia. The mixture will again become discolored, and must be cleared by adding a few drops of acetic acid. Filter and place in a glass-stoppered bottle. Fasten a sheet of the salted paper to a flat board, and with a soft wide brush apply the solution, brushing first one way of the paper and then the other. Brush very lightly so as not to roughen the paper. The solution must be applied by gas or lamp light, and the paper dried in the dark. When dry it is ready for printing. The prints should be deeper than those made on aristo-paper. Tone in any good combined bath. The following formula may be used; and is also suitable for any mat-surface paper: Dissolve 1 oz. of hypo in 6 oz. of water, and filter. Dissolve 7-1/2 grains of pure trichloride of gold in 1 oz. of water. Add this gold solution drop by drop to the hypo solution, shaking the mixture frequently during the operation. This is a stock solution. To prepare the toning bath take 1-1/2 oz. of this stock solution and mix it with 7-1/2 oz. of a ten-per-cent. solution of hypo. (A ten-per-cent. solution is made by dissolving 1 oz. of hypo in 9 oz. of water.) Place the prints in this bath without previous washing, and tone to the desired color. Almost any tone from reddish-brown to black may be obtained, the tone depending on the length of the time the print is left in the toning bath. Wash well and pin on a flat board, and set the board in an upright position till the prints are dry. The paper is of sufficient weight not to require mounting, and the paper should be cut large enough to leave a wide margin all round the print. For a 4 by 5 picture cut the paper 8 by 10 inches. In printing, the paper--except where the picture is to appear--should be covered. Take a piece of opaque paper the size of the sensitized sheet, and cut an opening in the centre a little smaller than the negative from which the print is to be made, and print the picture through this opening.