US241070A - Thomas o - Google Patents

Description

.go to the other, a little at atime, shaking well the formed--will not answer.

{.INITE STATES THOMAS C. ROCHE, OF BROOKLYN, ASSIGNOR TO E. 86 H. T. ANTHONY & G

.. OF NEW YORK, N. Y.

PHOTOGRAPHIG PAPER.

, SPECIFICATION forming part of Letters Patent No. 241,070, dated -May 3, 1881 Application filed February 8, 1881. (No specimens.)

To all whom it may concern: latter at each addition. I then put the bottle Be it known that l, THOMAS C. Room-1, of now containing the united solutionsinto stemthe city of Brooklyn,- in the county of Kings ered light-excluding vessel containing water, and State of New York, have invented a new the temperature of which is raised and kept up and useful Improvement in Photography, of to between 80 and 110 Fahrcuheitfor two or which the following is a specification. three days, occasionally shaking the bottle, so One of the comparatively niodern'improveas to keep the contents thoroughly mixed. mentsinthenrtofnegativephotographicpriut- ,Each days cooking makes the solution more big consists in the successful use of gelatine sensitive. I can,'by raising the temperature to sensitized by a bromide of silver applied as a the boiling-point and maintaining it fora short coating to the glass plate forreceiving the negtime-say one totwo hou'rs '-acc0mplish nearly ative photographieimpression,asensitized gel the same result; .but I prefer the efi'ect the atine solution having been discovered and procooking more slowly produces. After the soduced whiclnwhen thus employed in negative lntion has been thus cooked pour it into a 5 printing, is possessedot' suchextreme sensisuitable dish-preferably glass or porcelaiu-- tiveness as to enable a sati factory'photoand permit it to cool and set. Ithen divideit graphic impression to be secur d very quickly, up into smallpieces and put it into a suitable and even by a feeble artificial light; but sofar holder for washing-a coarse canvas bug or an as I am aware'the use of this gelatine solution earthen vessel with perforations in the bottom.

.0 has been hitherto confined to negative print- I then allow cold water to run onto it fora few 7o ing, and has not, until my present-invention, hours, occasionally stirringup the massto wash been successfully, if at all, employed in pos'i-' out all soluble matter, such as nitrate of amtive printing. It is possible that. a gelatine mania and excess of-bromide, if any remain. solution may have been laid upon paper; bntit I then dissolve the gelatine thus prepared by so the paper has. been employed only as a heatand add toitabout an equal quantity, by 5 tissue on which to form a. pellicle intended fluid weight, of water, thus forming a solution to he removed and used as a negative. I have that contains no free nitrate of silver, and that succeededincombiningagelatiue solution senis much thinner than is suitable forjuse on sitized with a neutral bromide of silver with plates for negative printing. It is essential o photographic paper, whereonpositive photoin negative printing that the solution should 8o graphs may be successfully taken under a be snificieutly concentrated to form a comparnegative almost instantaneously, and even atively thick and opaque film on the plate.

by the light eta common oil-lamp. When thus concentrated it will not answer to lwill proceed to describe my method of thus apply to paper for positive printing. In the 35 combining sensitized gelatine with paper. latter it is essential that the sensitized gela- 8 5 y The solution I prepare is as follows: I put tine shall be applied in an exceedingly thintogether in a. proper vessela glass bottle prefilm, and that it, in some measure,.penetrate i'erred-ot' good gelatine, (preferably French and become incorporated with theorganic inatgelatine,)say,onehundred and fifty grains, broter of the paper. l

4 0 mide of ammonia sixty grains, and water five The solution being thus prepared, it is ready go ounces. When the gelatine has softened I put for use on paper; but now it is necessary to thebottlejn a water-bath and raise the temhave regard to the condition of the paper to perature sufliciently to dissolve'the gelatine which it is to be applied, Paper suitable for say to '90 or Fahrenheit. In another tissues-that is, paper the pores or interstices 4 5 bottle I dissolve, say, one hundred grains of of which have been filled with some prep- 5 nitrate of silver in five ounces of water, and aration that prevents the gelatine solution then in a room in which there is only non-actinic from penetrating the surface of the paper and light I mix the contents of the two bottles tocauses it toserve the purpose of a simple tabgether by adding the silver solution gradually let or plate on which a removable pellicie is It must be common reg 2 V anew unprepared or unfilled photographic paper as it comes from thdmanufacturer. If it is entirely unsized and merely calendered, all the better. I take paper such asI have described,

5 and apply the solution either by flowing; itv

over the paper, by floating the paper. on the solution, orin any other suitable manner. The

paper is then, hung up and allowed to dry, wnen itis-readytbr use.

1o v-All' the operations must, of course, be carriedaon. in arooi is excluded.

from which all actinic light Paperthus-prepared, having on it no free .hnitrate of 'silyeu'will keep an indefinite time 25 ing to bring-ontg-tbe image fully.

x1 am aware ,t

suclras. Lila-V6 described has been made and used in negative printin g on plates and tissues,

except that ithas always been made and used 0 ina concentratedstate, so as to form a pellicle upon the plate or tissue, and not to penetrate or become combined withthe organicim'atter of. the paper. As is obvious, it is highly desirable to. be ablegto use this highly-sensitized 5 gelatitre sol u tionv ;;for positive 'priifti'ng'bn' pa per; but I ain--;n'ot aware that any successful hat a solution substantiallymethod of so doing has ever been known or practiced in this country or published or patcute-d anywhere before my present invention. j

1 WhatIclaim as my invention,and desire to secure by Letters Patent, is-, p v 1. The methodlierein described of combining sensitized gelatiue withpaperct'or positii e pbotographicprintingtconsisting"in first softening the gelatiue ines-ater and adding the l bromide of ammonia'or an equivalentbromide, using about theproportions named; then dis solving the gelatine by heat and adding gradually'nit-rate of silverdissolred in water in about the proportions named; then continuing 5 the heat at about 80? or 100 Fahrenheit for two or three days; then, afterallowing itte cool and set, cutting it into fragments and washing out the soluble matter; then tne'lting it by heat and addingaboutitsweight of water; then an 5 plyjmg it to unfilled pbotograpliic paper, into which penetrates, and with'th'e organic mat ter of which it combines; lastly, dryingit in any suitablemanner, allas, and for thepnrpose described. p 6 2. As a new-article of manufacture, unfilled. and unglazed photographicpaper for positive. printing, with the face of which. is combined. a sensitive substance consisting, essentially," of 'gelatine'and a bromide of silver, substamj 6 tially as specified; .Witness my band this 5th dayof February,

f THOMAS OJ ROCHE. In presence otj fl. g KiilfiN G. W; VERMILYA,- HENRY Erasmus.