We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
1949
SPRAY PROCESSING
675
light of the results obtained, it was thought necessary to repeat some of the more significant runs with the positive developer adjusted with bisulfite to pR 10.0.
Oxidation Rates in the Five Systems
Since it was thought possible, that the presence of colloidal silver might influence the rate of oxidation, most of the runs were repeated after adding about 0.014 gram of colloidal silver suspended in a gelatin sol, per liter of developer. When, as will be discussed later, it was established that it did not affect the rate of oxidation, its use was discontinued. Figs. 5, 6, and 7 illustrate typical exhaustion runs and
HYDROQUINONE
WITH COLLOIDAL
—I i i i * i * —
TIME (HOURS)
Fig. 7 — Change of composition of the positive developer at pH 10.5 in the airbubbling system.
give some idea of the fair degree of reproducibility that was obtained in the rates of oxidation. The runs with colloidal silver may be taken as duplicates of those without. For lack of space, full plots of all the runs will not be given ; instead, the initial rates of oxidation in terms of grams per liter per hour are given in Table I. Because of its apparent lack of effect, a number of the runs shown in Table I have no counterpart with colloidal silver.
Before discussing the results in detail, it is necessary to comment upon the rather wide deviations that are shown in Table I in the initial concentrations of Elon and hydroquinone. These deviations, which do not materially affect the results, arose from the fact that, in order to expedite this somewhat lengthy work, the baths were made up slightly overstrength, with respect to the developing agents, to allow