Turning A Negative Into A Positive

A short time ago a developed píate was sent to the editor by one of the meinbers of the Camera club on which the image was partly reversed - that is, instead of beiiig a uegative it was almost a positive. The cause of this is what is termed solarizatiou - in other words, the píate was very much overexposed, aud on developrnent carne out a positive iustead of a uegative. lí a píate coated with silver salts is exposed in the camera or uuder a negative bevond a certain time, a change takes place in the silver salts, which resulta in a positive insteadof a negative. Tlïis is the reason why objects which refkct light strongly show clear glass in ti.e negative. They are overexposed, aud the image produced is a positive. There are several processes by which a negative ruay be turnedjnto a positive during the process of development. One of the simplest is as follows: Expose the píate as for an ordinary negative and develop until the image may be seen distinctly on the back of the píate. Einseoff the developer, and place the plate in a solution made up of a quarter ounce of iodide of potassium, 2% ouncesof bromide of potassium aud 25 ounces of water. Let it remain in this solution from three toflve miuutes, wash well in ruiming water, and tóen redevelop the plate with fresh developer, contiuuiug the operation till the negative image has turued to a positive. Rinse the plate, fix and wash in the sarue way as for an ordinary negative. Pyro or ferrous oxalate gives the Liesfc results, but any developer may be useci. A plate thus treated may be used as