This mode of taking negative photographs begins where the talbotype ends--viz., by _first_ waxing the paper perfectly and evenly, as already explained, Cansan's negative paper being preferred. The wax paper is now well soaked in a bath, made by dissolving one hundred grains of iodide of potassium, six grains of cyanide of potassium, four grains of fluoride of potassium, ten grains of bromide of potassium, ten grains of chloride of sodium, in one pint of fresh whey, with the addition of a little alcohol and a few grains of iodine. When soaked in this solution for about one hour, the paper is taken out and hung up to dry. N.B. With respect to iodizing the wax paper, it is almost better to obtain it ready prepared, and then every sheet may be relied on. Mr. Melhuish, of Blackheath and Holborn, supplies it in any quantity, and his paper never fails; the operator has then only to perform the sensitizing and developing processes. To render the iodized paper sensitive it is immersed for about six minutes in a bath containing a solution of nitrate of silver (thirty-five grains to the ounce of water, with forty drops of glacial acetic acid); the paper is now removed, and washed in two trays of common clear rain-water or distilled water, and is then dried off between folds of blotting-paper. This process may be performed on the previous evening by the light of a candle, or by day in a room lit by one window covered with four thicknesses of yellow calico, and after the paper is dry it will keep for three [Page 145] weeks or a month, and may be exposed in a camera with a three-inch lens of eighteen-inch focus, with the inch diaphragm, on a bright day from five to fifteen minutes; in bad weather the exposure must be longer. The picture may be carried home and rendered visible or developed by immersion in a bath containing a saturated solution of gallic acid, and as the developing continues, a few drops of the sensitizing solution of nitrate of silver and glacial acetic acid may be added. Finally, the picture is fixed by immersion for a quarter of an hour in a solution of hyposulphite of soda (four ounces of the crystal to one pint of water, or one part of the saturated solution to eight of water), and being well washed, is then dried, hung before the fire to melt the wax, and is now ready to print from. _Fifth Experiment. Albumen on Glass Process._