An Integrating Machine
sub·bromide. In tbe sbady parts less silver is deposited. ments, to find out some means by which tbis opalescence When tbc image is once started it follows tbat partic1es of might be got rid of in tbe most convenient manner . Cement· IT is quite possible tbat in tbe remark;; I propose making silver produced by tbe iron developer will cause more to fall ing tbe transparency to a piece of plain, clear glasJ witb this evening in connection witb tbe pbotograpbic art I may down on tbe face of tbose
... tbe face of tbose already present, and tbe image is, Canada balsam, as suggested by MI'. Woodwortb, I foundin mention topics and some details wbich are ramiliar to many of course buHt up if tlle silver nitrate be all consumed on practice to be open to two formidable objections , . One öf present; but as cbemistry and optical �ud pbysical pbeno· tbe plate.' Tbe develop�l' then becomes useless 01' injurious , these was that Canaßab:tlsam used in tbis manner is a sticky, mena enter largely into tbe tbeOl"y and practice of pboto-Tbe presence cf acetic acid cbecks tbe,reduction of tbe unpleasant SubstlU}ce to meddle witb, aud takes a long time grapby, tbe field is so extensive tbere is always sometbing silver, and tbe alcobol facilitates t , h� fiow wben the batb I :n e�rly a montb-to barden �be? confined between . plates interesting and suggestive even in the l'udiments, especially becomes charged witb etber and spmt . m tbls pIanller. Tbe otber obJectlOn was of extreme Impor· to those wbo are commencing their studies. Altbougb tbis The molecular attraQtion just men��:med is made plainer j ' tance, n!lmely, that, in consequence of commercial gelatine paper may be,considered an introductory one, I do not wisb by reference to tbe simple lead tree e�petiment. We bave plates not being prepared on perfectly fiat glasses in an cases, to load it witb any bistorieal account, ur describe tbe early here in tbis bottle a piece of zinc 1'9d introduced into. a solu· I found tbat, after squeezing out tbe superftuous balsam and metbods of prpducing a ligbt picture, but sball at ouce take tion of acetate of lead , A cbemical Cljl\ng;i'bas taken P lace, ! the air bubbles tbat migbt have formed from between tbe for my subject, "Tbe Photograpbic Image: Wbat It Is," The ztnc has abstracteJ tbe acetic acid and the lead is . two plates, tbey are liable to separate at the places wbere and Ilnder this beading I must restrict myself to tbe collodion depo . sited on thc zinc, and will continue to be so until the I tbe transparency is not fiat, causing air bubbles to creep in aud silver or wet proeess, leaving gelatine dry plates, col· e olution is exbausted. The irregularities of surface and from the edges, as you may see from these examples. L lodio·cbloride, platinum, carbontype, and the numerous arborescent appearance are weil sbown . If tbe cbange were I tberefore, bave discarded t.his method, although it had tbe other types wbich, are springing up in all directions for rapidly conducted tbe lead particles would from their etIect desired wben successfully done. future conside1)l.tion.weight sink rlirectly to tbe bottom instead of aggregating I bave bit, however, upon another way of utilizing Canada Now, in an orrl inary pencil, pen and ink, 01' sepia sketcb together like ordinarv crystals. I bave constructed a dia· balsam, wbich, wbile retaining all tbe good qualities of the we bave a deposit of a dark, non·reftecting substance, wbicb ° former metbod, is not subjPct to any of its disadvantages. gives the outline of a figure on a lighter background. The This consists in diluting tbe balsam witb an equal bulk of different gradations of sbade are acquired uy a more 01' less turpentine, and using it as a varuish, pouring it on like col· deposit of lead, ink, or sepia, In photography-at least in lodion, fiowing it toward eacb corner, and pouring it off into the ordinary silver process-the image is formed by a de· the boUle from tlie last corner, avoiding crapy lines by position of metallic silver 01' organic oxide in a.minute state slowly tilting the plate, as in varnisbing, If the plate be uf division, either on glass, paper, or otber suitahle material, warmed previously, the vamisb fiows more freely andleaves This is brought about hy the action of light and certain rea thinner coating of balsam behind on the transparency, agen t s. Ligbt bas long been recognized as a motive power Wben the plate bas ceased to drip, place it in a plate mainer, comparable with beat 01' electricity , Its action upon tbe witb the corner you poured from luwest, aod leave it wbere skin, fading of colors, and effect on tbe growtb of vegetable dust , cannot get at. it . for four 01' five days, when it will· !Je !tnd animal organisms are weil known; and, although tbe found sufficiently hard to be put into a plate box. The trans· exact moleculaI' change in many instances is not clearlr d Silver deposi t-I mage. c Sub·bromide anrl sub·cblor!de parency may be finished at any time afterward by putting a © 1881 SCtENTtFtC AMERtCAN , tNC Wo also send free our Hand Boo k aboßt tbe Patent Laws. Paten's, Cavell ts. Trade MarkS j their MSts. snd how procured, \Vitb hints 'or procuring ndvnnces on llvenl.ions. Addres. DIUNN k (JO., 37 Park Row, '!Vew York. Bmllch Offi ce, cor, F lind 7th 518., Washington, D. C.