153. Citric acid may be substituted for phosphoric acid. Dissolve 8 ozs. of citric acid in 8 ozs. of hot water and place in a bottle labeled "Citric Acid Solution."

154. Prepare the Platinum Stock Solution as follows:

Chloro-Platinite.................................

15 grs.

Citric Acid Solution........................................

1 Oz.

Water..........................................

1 Oz.

Shake until the platinite is thoroughly dissolved. For use take:

Water..........................................

30 Ozs.

Citric Acid Platinum Stock Solution...........................

,2 drms.

155. Toning In The Platinum Bath

Toning In The Platinum Bath. When the prints are thoroughly washed and free of the alkali from the gold bath place them in the platinum bath a few at a time. It is advisable to test this bath with a single print in the same manner employed for testing the gold bath. Keep the prints in motion and leave in the platinum bath until all trace of red in the very deepest shadows has disappeared. Do not be afraid of toning too far in the platinum bath, as this is almost an impossibility. Detailed instruction for toning in the platinum bath is thoroughly covered in the following chapter.

156. Washing The Prints After Toning In The Platinum Bath

Washing The Prints After Toning In The Platinum Bath. Because the platinum bath is extremely acid and as it is absolutely necessary to remove all acid from the prints before placing them in the hypo bath, the prints must be thoroughly washed in not less than three changes of clear water before fixing. If acid were carried into the hypo bath, sulphurization would at once take place and the whites become yellow.

157. Fixing

Fixing. Hypo baths containing alum, or other acid hardeners are dangerous, and should not be used as the acid releases the sulphur in the hypo and produces sulphurization in the prints, which will ruin them sooner or later. After prints are washed, fix in a plain hypo bath for 15 minutes. The bath should be composed of 64 ozs. of water, in which has been thoroughly dissolved 4 ozs. of hyposulphite of soda, or 18 hydrometer test.

158. Salt Bath

Salt Bath. After the prints are fixed, it is a good plan to transfer them at once to a salt bath, using 4 ozs. of common table salt to every gallon of water. Constantly separate the prints and leave them in this bath for five minutes.

159. Final Washing

Final Washing. The prints should be thoroughly washed by hand, giving them not less than 12 changes of water, picking them over between each change. They can be washed in running water, but even then the same care should be given to continually handle the prints, picking up and separating them so that each and every print will be thoroughly washed. The permanency of the print depends largely upon freeing it from the hypo and other soluble chemicals which, if allowed to remain in the emulsion of the print, would, in time, cause a fading and deterioration of the image. If running water is used wash them for one hour. The safest plan however is to wash by hand.

Note. - Strong solutions of borax and acetate of soda are somewhat affected by change of temperature, and where any difficulty is experienced in their use, a 10% solution, or even a solution 1 to 16, should be substituted, using a larger quantity, which will give practically the same results as the stronger solution.

PORTRAIT Study No. 8 By J. E. Mock

PORTRAIT Study No. 8 By J. E. Mock.

OFF TOMPKINSVILLE, NEW YORK HARBOR Study No. 9 By Dr. A. R. Benedict

OFF TOMPKINSVILLE, NEW YORK HARBOR Study No. 9 By Dr. A. R. Benedict.

See Page 3S6