Make a strong solution of chlorinated lime; dip the fingers which are stained in this, and rub the stains with a large crystal of citric acid. Apply the lime solution and acid alternately until the stain is removed; then rinse with water.

To Remove Pyro Stain from Negatives

Immerse in a clearing bath as follows:

Protosulphate of iron. 3 ounces

Alum .. ,........... 1 ounce

Citric acid.......... 1 ounce

Water.............. 20 ounces

Prevention is better than cure, however; therefore immerse the negatives in the above directly they are taken from the fixing bath. After clearing the negatives, they should be well washed.