This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 Excerpt: ...Heat it slightly and filter it to free it from the iron and carbonaceous matter it may contain. The liquid then gives, by evaporation, crystals in the form of four-sided prisms, which are deliquescent. This salt, added to the aceto-nitrate of silver, plays nearly the same part as nitric acid. It appears to slightly ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 Excerpt: ...Heat it slightly and filter it to free it from the iron and carbonaceous matter it may contain. The liquid then gives, by evaporation, crystals in the form of four-sided prisms, which are deliquescent. This salt, added to the aceto-nitrate of silver, plays nearly the same part as nitric acid. It appears to slightly increase the sensibility of the paper and preserves the whites of the proof by precipitating into the texture of the paper a white oxide of zinc, insoluble in water, and which will close up all the pores of the paper. It must not be left long in the iodide bath, because the precipitate might be re-dissolved in the alkaline solution. After taking the paper from the bath, hang it up to dry, and use it upon the ordinary aceto-nitrate paper. Nitrate of zinc, on account of its deliquescent quality, has been recommended for prolonging the sensitiveness of collodion on glass. Mr. Brookes, who first employed it, recommended that it should be dissolved in a small quantity of water, and the liquid poured over the sensitive plate; he now gives the preference to nitrate of magnesia. Nitric Acid. This acid is composed of 1 part nitrogen and 5 of oxygen. It may be obtained by distilling saltpetre or nitrate of potash with oil of vitriol. It is found abundantly in commerce; it is used in photography to form the nitrate of silver and the chloride of gold, by its union with hydrochloric acid. It may also be employed to blacken positive proofs, by adding it to the hyposulphite of soda solution. In a diluted state it is employed with rottenstone to clean the daguerrotype plate; 10 to 15 drops to the ounce of water being sufficient. Nitric acid is a powerful solvent for metallic bodies generally. To illustrate its action in that particular, as contrasted with other ...
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