American Photography Volume 2

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. 1908 Excerpt: ...the defective character of the negative or through errors of judgment in making the print, may be treated with solution 4 or 5, according to the degree of strengthening required, and a very satisfactory result obtained, when, without such treatment, the print would be valueless. Prints that are weak through under-exposure will yield a slightly colder tone than that produced by treating normally exposed prints in the same bath. Over-exposed prints will be distinctly warmer. Soon after the introduction of sulphide toning, the fact was published that sodium sulphantimoniate--Schlippe's salt--might be substituted for sodium sulphide, for darkening the bleached image. A solution may be prepared in the same manner as that described for sodium sulphide. When the solution is filtered a dark precipitate will be found on the filter paper, and the clear solution will be a pale straw color. It will keep indefinitely. The working solution should be: --Sodium sulphantimoniate 4 grains Water i ounce This is prepared by taking 40 minims of the stock solution for every ounce of When this solution is used for darkening the prints, bleaching solution No. i is the only one that should be used. Mercury must not be employed on any account. There is no advantage to be derived from its use, but a very strong tendency to yellow staining. Prints bleached in solution i--the simple ferricyanide and bromide--and then darkened by means of sodium sulphantimoniate, tone to a red color, almost as bright as red chalk carbon prints. The sulphide and sulphantimoniate solutions may be combined in various proportions to produce tones intermediate between those given by either solution used alone. Details and formulas giving the proportions necessary for obtaining the different shades of color wi...