The Photographic art-journal . sufficient importanceto bring before the consideration of thePaiis Academie des Sciences :—Takeone kilogramme of Cologne glue ; dissolveit in one litre of water in a glazed pot bymeans of a gentle heat, that of a water-oath being most eligible, taking care to agi-tate or stir it from time to time. As soon as all the glue has become melted pour in-to it veiy gradually, and by small portions,200 grammes of nitric acid of 60 degreesstrength. This addition produces an ef-fervescence due to a disengagement of by-ponitrous acid. When all the acid hasbeen poured in, the
The Photographic art-journal . sufficient importanceto bring before the consideration of thePaiis Academie des Sciences :—Takeone kilogramme of Cologne glue ; dissolveit in one litre of water in a glazed pot bymeans of a gentle heat, that of a water-oath being most eligible, taking care to agi-tate or stir it from time to time. As soon as all the glue has become melted pour in-to it veiy gradually, and by small portions,200 grammes of nitric acid of 60 degreesstrength. This addition produces an ef-fervescence due to a disengagement of by-ponitrous acid. When all the acid hasbeen poured in, the glue pot is to be re-moved from the fire and its contents allow-ed to cool. M. Dumoulin has preservedglue thus prepared for more than two yearsin an uncorked flask. It had undergone noalteration. Glue thus prepared is paiticu-larly useful for attaching paper to drawingboards, and for serving as a chemical lute,in addition to the many other purposes t®which it may be 186 The Photographic Art-Journal. March HE approachingWorlds Fair in NewYork will, we ventureto say, contain an ex-hibition of daguerreanand paper photographssuch as the world neversaw before. There hasbeen a studied silence uponthe part of the Europeanpress in regard to the Ame-rican daguerreotypes exhi-bited at the Exposition ofall Nations in London, that doesthem little credit. We se3 daguerreotypes, byEnglish, French, German and Italian art-ists, extolled to the skies, while those ex-hibited by Americans are ei her passedover in silence, or receive that faint praise,which is better calculated to create con-tempt than a just and impartial too is done when the very writersthemselves must acknowledge to their ownhearts the superiority of the American da-guerreotypes, and with the fact, also staringthem in the face, that to Americans thehighest prizes were awarded. We must, under the circumstances, con-sider, that the minds of these wriers areeither most egregiously warped by p
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectphotogr, bookyear1851
