_New Developing Mixture._--Having for some months past used the following
developing mixture, and finding it very bright and easily applied, I beg to
offer it to your notice. It does not cost more than three farthings per
ounce, and therefore may be worth the consideration of beginners. I do not
know a better where the metallic appearance is not desired.
No. 1. Pyrogallic acid 2 grains.
Glacial acetic acid 1 drachm.
Water 1 oz.
No. 2. Protosulphate of iron 10 grains.
Nitric acid 2 drops.
Water 1 oz.
To six drachms of No. 2. add two of No. 1.
I pour it on, but do not return it to the bottle, as it is apt to spoil if
so used.