72 Paper Process in Photography. [no. 1, new series, 



exciting dish must never be used for developing, and the dishes for 

 developing solutions should not be used for any other purpose, ex- 

 cept washing the paper after it is excited, in which case if clean 

 they are not likely to do any harm. After being used with Gallo- 

 nitrate they should be washed as soon as possible in abundance of 

 clean water, and if the Gallo-nitrate solution decomposes rapidly 

 when placed in them, they must be washed with a weak solution 

 of Cyanide of Potassium (5 grs. to one ounce of water), and with 

 plenty of clean water afterwards. The trays for Hypo-sulphite 

 cannot be used for any other purpose except for washing the finish- 

 ed negative. The Photographer will also find it advantageous to 

 have separate measure and funnels for his Aceto-nitrate and Gallic- 

 acid solution. 



Paper. 



The paper used in this process is Canson's thin Negative. It is 

 not without imperfections, such as unevenness of texture and mi- 

 nute holes which allow the exciting, and developing solutions to 

 pass through and stain the back of the negative. To the beginner 

 these things are not of much importance, as he must expect to spoil 

 a few papers, but when a little more advanced, he should examine 

 his papers carefully by a strong light, rejecting any that have the 

 imperfections above noted which need not however be thrown away, 

 as the best will do for waxing which fills up any very small holes, 

 and the remainder will do for Positives. The papers should be cut 

 of the same width and half an inch or so longer than the Camera 

 slide ; one side of the paper is smoother than the other which is 

 best ascertained by holding it so that the light falls upon it oblique- 

 ly ; this should be marked in two opposite corners with a capital 

 letter, which better defines the side on which the mark is made 

 than a circle or cross. 



Iodizing. 



The solvent may be either whey or distilled water, I believe the 

 former produces the most dense skies and a greater opacity gene- 

 rally in the dark parts of the picture, it is however somewhat 

 troublesome to prepare :— the following method of obtaining it, is 

 perhaps as good as any. 



