3178. Albumenized Paper for Positive Printing

3178.     Albumenized Paper for Positive Printing. "White of egg, and water, equal parts; iodide of potassium or chloride of sodium, 5 grains to 1 ounce water (or bromide of potassium, 20 grains). Coat the paper with this solution. Dry. Immerse in the dark in bath of 120 grains nitrate of silver to 1 ounce water. Dry again. This is exposed with the negative over it, for 10 to 15 minutes.

3179. Prepared Wax Paper

3179.    Prepared Wax Paper. Make a strong size by digesting 25 parts gelatine, 50 of linseed, and 150 of rice flour, in 2000 to 3000 parts hot water. Filter through a cloth. Take of this size, when cold, 1000 parts by weight, and dissolve in it sugar of milk, 50 parts: iodide of potassium, 35; bromide of potassium, 5 parts.

3180. Artificial Ivory for Photographers

3180. Artificial Ivory for Photographers. Sheets or tablets of gelatine or glue are immersed in a solution of alumina. When entirely penetrated by the alumina, the slabs are to be removed, dried, and polished like ivory. (Mayall.)

3181. Barytic Photographic Solution

3181.   Barytic Photographic Solution. Dissolve 35 grains chloride of barium in 2 ounces distilled water.

3182. Chromate Photographic Solutions

3182.    Chromate Photographic Solutions. Simple chromate solution is a saturated solution of bichromate of potash; a little sulphate of indigo being sometimes added to vary the color.

The compound chromate solution consists of 10 grains bichromate of potash, and 20 grains sulphate of copper, dissolved in 1 ounce distilled water.

3183. Hydriodate of Iron and Bary-tes Photographic Solution

3183.    Hydriodate of Iron and Bary-tes Photographic Solution. Hydriodate of barytes, 40 grains; water, 1 ounce; pure sulphate of iron, 5 grains; mix, filter, add a drop or two diluted sulphuric acid, and when settled decant the clear liquor for use.

3184. Hardwich's Gold Toning Bath for Positive Printing

3184.    Hardwich's Gold Toning Bath for Positive Printing. Pure chloride of gold, 1 grain; hyposulphite of soda, 1 to 3 grains; hydrochloric acid, 4 minims; water, 4 ounces.

3185. Mayall's Method of Cleaning Photographic Glasses

3185.    Mayall's Method of Cleaning Photographic Glasses. Shake up together 30 parts alcohol, 10 parts strong liquid ammonia, 40 parts water, and 30 parts fine Tripoli. The plates are to be rubbed hard and evenly with balls of cotton-wool dipped in the mixture. When dry, rub again with a clean ball of cotton, and dust off the back and edges with a clean hog's-hair brash.