A manual of photographic chemistry, theoretical and practical . hed with moist hands, or hands contamin-ated with chemicals, and when not in use they should be storedaway in a clean cotton bag, and in a dry place. TO COAT THE PLATE. When the salted collodion has settled for some days, decantoff a portion into a pouring bottle for use, taking care not to WET COLLODION PKOCESSES. 231 disturb the sediment. The best, and at the same time cheap-est, pouring vessels are the tall lipped medical bottles, procur-able at any druggists. They must be fitted with the bestcorks, so as to prevent the evapora
A manual of photographic chemistry, theoretical and practical . hed with moist hands, or hands contamin-ated with chemicals, and when not in use they should be storedaway in a clean cotton bag, and in a dry place. TO COAT THE PLATE. When the salted collodion has settled for some days, decantoff a portion into a pouring bottle for use, taking care not to WET COLLODION PKOCESSES. 231 disturb the sediment. The best, and at the same time cheap-est, pouring vessels are the tall lipped medical bottles, procur-able at any druggists. They must be fitted with the bestcorks, so as to prevent the evaporation of the ether and take a glass plate, previously cleaned, and wipe it gentlywith a broad camels-hair brush, in order to remove anyparticles of dust which may have subsequently collected. Ifit be a plate of moderate size, it may be held by the corners ina horizontal position, between the forefinger and the thumb ofthe left hand. The collodion is to be poured on steadily untila circular pool is f 6rmed, extending nearly to the edges of Fig. 10. By a slight inclination of the plate the fluid is made to flowtowards the corner marked 1 in the above diagram, until itnearly touches the thumb by which the glass is held; fromcorner 1 it is passed to corner 2, held by the forefinger ; from2 to three, and lastly, the excess poured back into the bottlefrom the corner marked No. 4. It is next to be held over thebottle for a moment, until it nearly ceases to drip, and then, byraising the thumb a little, the direction of the plate is changed,so as to give a rocking movement, which makes the diagonallines coalesce, and produces a smooth surface The operationof coating a plate with collodion must not be done hurriedly,and nothing is required to insure success but steadiness ofhand and a sufficiency of the fluid poured in the first instanceupon the plate. In coating larger plates, the puematic holder, whichfixes itself by suction, will be found the most simple and use-
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Keywords: ., bookcentury1800, bookdecade1880, bookidma, booksubjectphotography
