US641919A - Process of intensifying photographs. - Google Patents
Process of intensifying photographs. Download PDFInfo
- Publication number
- US641919A US641919A US72456999A US1899724569A US641919A US 641919 A US641919 A US 641919A US 72456999 A US72456999 A US 72456999A US 1899724569 A US1899724569 A US 1899724569A US 641919 A US641919 A US 641919A
- Authority
- US
- United States
- Prior art keywords
- parts
- intensifying
- sulfocyanid
- photographs
- mercuric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
- G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
- G03C5/268—Processing baths not provided for elsewhere, e.g. pre-treatment, stop, intermediate or rinse baths
Definitions
- the first method consists in using mercuric chlorid as intensifier, by the action of which the black silver print is first bleached, assuming a greater transparency. After washing thoroughly the print is again densified and darkened by treatment with ammonia or sodium sulfite, whereupon it is washed once more.
- the second method consists in using as intensifiers uranium salts. This process only requires one operation. However, the
- the invention is illustrated by the following exam lesi First. en parts of mercuric sulfocyanid and eight parts of potassium sulfocyanid are dissolved in one hundred parts of distilled water. This stock solution, which can be kept without decomposing, is diluted with ten parts of water for use as intensifier. The negative or positive which needs intensifying is placed into the diluted solution and left therein, while preferably keeping the liquid in motion until the desired degree of intensification is reached. The intensified negative or positive is then Washed and dried.
Description
UNITED STATES PATENT OFFICE.
MOMME ANDRESEN AND ERNST LEUPOLD, OF BERLIN, GERMANY, ASSIGN- ORS TO THE AOTIEN-GESELLSOHAFT FHR ANILIN FABRIKATION, OF
SAME PLACE.
PROCES$ OF INTENSIFYING PHOTOGRAPHS.
SPECIFICATION forming part of Letters Patent No. 641,919, dated January 23, 1900-.
A Application filed July 20,1899. Serial No- 724,569. (No specimens'i) I To all whom it may concern.-
Be it known that we,MOMME ANDREsElN and ERNST LEUPOLD, of Berlin, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in Intensifying Photographic Silver Prints; and we do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to [O which it appertains to make and use the same.
For intensifying photographic silver prints, (negatives or positives,) especially in the negative process, with gelatine silver bromid two methods have heretofore principally been I 5 ,nsed. The first method consists in using mercuric chlorid as intensifier, by the action of which the black silver print is first bleached, assuming a greater transparency. After washing thoroughly the print is again densified and darkened by treatment with ammonia or sodium sulfite, whereupon it is washed once more. The second method consists in using as intensifiers uranium salts. This process only requires one operation. However, the
intensive red-brown color produced in the print by the action of the uranium salts is not at all stable, and besides the degree of the intensification attained cannot be safely calculated. Moreover, the uranium intensifier does not keep, but is decomposed in a short time. WVe have now found that the double salts of mercuric sulfocyanid yield solutions which keep well and which intensify the photographic silver print with black color in a single operation. Of the double salts of mercuric sulfocyanid, especially those formed with sulfocyanids or with chlorids of the alkalies, alkaline earths or ammonia or mixtures of the same can be practically used.
0 I The proportions in which we dissolve the above constituents in order to produce the new intensifiers are not exactly those calculated for the formation of the double salts from equimolecular quantities of mercuric sulfocyanid with the sulfocyanids or chlorids of the before=mentioned alkalies, since an excess of the alkali salts has been found suit able, as the mixtures so obtained are easier soluble in water and more stable in aqueous solution than are the pure double salts.
The invention is illustrated by the following exam lesi First. en parts of mercuric sulfocyanid and eight parts of potassium sulfocyanid are dissolved in one hundred parts of distilled water. This stock solution, which can be kept without decomposing, is diluted with ten parts of water for use as intensifier. The negative or positive which needs intensifying is placed into the diluted solution and left therein, while preferably keeping the liquid in motion until the desired degree of intensification is reached. The intensified negative or positive is then Washed and dried.
Second. Ten parts of mercuric sulfocyanid and ten parts of sodium chlorid are dissolved in fifty parts of water. For use as intensifier this stock solution is diluted with ten parts of water.
Third. Ten parts of the double salt of mer- 7e curic sulfocyanid with potassium sulfocyanid and six parts of sodium chlorid are dissolved in fifty parts of water. For use as intensifier this stock solution is diluted with ten parts of water. 7' 5 Having now described our invention and in what manner the same can be performed, what we claim as new is The process herein described of intensifyin g photographic silver prints, which consists in subjecting the prints to the action of the herein-described solutions containing double salts of mercuric sulfocyanid.
In witness whereof we have hereunto signed our names, this 5th day of July, 1899, in the presence of two subscribing witnesses.
MOMME ANDRESEN. ERNST LEUPOLD.
Witnesses:
HENRY HASPER, WOLDEMAR HAUPT.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US72456999A US641919A (en) | 1899-07-20 | 1899-07-20 | Process of intensifying photographs. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US72456999A US641919A (en) | 1899-07-20 | 1899-07-20 | Process of intensifying photographs. |
Publications (1)
Publication Number | Publication Date |
---|---|
US641919A true US641919A (en) | 1900-01-23 |
Family
ID=2710502
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US72456999A Expired - Lifetime US641919A (en) | 1899-07-20 | 1899-07-20 | Process of intensifying photographs. |
Country Status (1)
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US (1) | US641919A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2467359A (en) * | 1946-01-23 | 1949-04-12 | Rubinstein Leon | Photographic oxidizers and resists |
US2764484A (en) * | 1950-10-03 | 1956-09-25 | Hartford Nat Bank & Trust Co | Method of forming photographic images by physical developing |
-
1899
- 1899-07-20 US US72456999A patent/US641919A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2467359A (en) * | 1946-01-23 | 1949-04-12 | Rubinstein Leon | Photographic oxidizers and resists |
US2764484A (en) * | 1950-10-03 | 1956-09-25 | Hartford Nat Bank & Trust Co | Method of forming photographic images by physical developing |
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