Proceebixgs of the Peotograehical Sectjox. 983 



February 6, 1872. 



Mr. H. J. Newton in the chair; O. G. Mason, Esq., Secretary. 



Mr. J. B. Gardner stated that albumen prints, fixed in a fresh solu- 

 tion containing one ounce of hyposulphite of soda to six ounces of 

 water, would remain much whiter than those fixed in a weaker solu- 

 tion. He believed that prints should be fixed in five or eight 

 minutes, and the same solution should be used only once. 



Mr. II. J. Newton spoke of a collection of prints which he exhi- 

 bited before the Society several years ago. They we're made on 

 albumen paper, sensitized on five, ten and fifteen-grain silver solu- 

 tions, and were fixed in the ordinary way. He had examined those 

 prints to-day, and found that they remained as pure in tone as when 

 new. lie was not able to detect any change. 



For sensitizing collodion, Mr. J. B. Gardner used sixty grains of 

 bromide of cadmium in twenty ounces of water, forty grains of iodide 

 of ammonium and forty grains of bromide of ammonium, dissolved 

 in one and one-half to two ounces of water. When the aqueous 

 solutions were added first to the collodion there was a tendency to 

 cloud, but when added last there was no such tendency. 



Mr. II. J. Newton exhibited a beautiful collection of negatives, 

 glass positives and photographic prints on paper, made by the 

 collodio-chloride process. 



The collodio-chloride had been prepared as follows : Twelve grains 

 of chloride of cadmium and twenty grains of citric acid were finely 

 ground and dissolved in two ounces of alcohol, then poured into an 

 eight-ounce vial, and forty-eight grains of prepared cotton added ; then 

 four ounces of concentrated sulphuric ether were poured on, and 

 shaking the vial frequently daring the pouring. The solution should 

 thereupon appear perfectly clear. In a clean mortar, grind — in the 

 smallest quantity of water that will dissolve it — forty-eight grains of 

 nitrate of silver, and add two ounces of alcohol; then mix the latter 

 with the previously prepared solution contained in the eight-ounce 

 vial, a little at a time, and in the meanwhile shaking the vial. Mr. 

 Newton albumenizes his glass with a solution of one part of albumen 

 and six parts of water, adding to each seven ounces of this solution 

 one-half dram of aqua ammonia. In the preparation of these 

 plates it is necessary to dry them immediately. After sensitizing, 

 they should be raised to a comparatively high temperature, and may 

 be exposed to any diffused light which would not be objectionable 



