PAPYROXYLINE (Fr., Papyroxyline ; Ger., Papyroxylin) Pyroxyline prepared from paper, usually pure tissue or filter papers, instead of from cotton wool. It was first introduced by Pelouze in 1838, and used by Crookes, Lyte, Elliott, Sutton, and Liesegang. It presents no particular advan tage over pyroxyline prepared from cotton-wool, and has fallen into disuse.
Para-amidophenol, para-amido phenol, and paramidophenol are other forms of this term.
In the form of a preparation by Lumiere, this developer is also known as " Paranol." It is a white crystalline compound, really para-amido phenol hydrochlorate which is widely used for making up highly concentrated developers in liquid form ; for example, rodinal. Amidol resembles, but is not identical with, para amido-phenol. A concentrated one-solution de veloper like rodinal may be made as follows :— Potass. metabisulphite . 3 oz. 33 oz.
Para-amido-phenol . i „ i io „ Distilled water (hot) . io „ 1,000 ccs.
Dissolve in the above order and add slowly a very strong solution of caustic soda or potash until the precipitate first formed is dissolved. For
use, dilute with io to 3o parts of water, an average strength being 24 drops to each ounce of water (1 in zo).
Developers may also be made up in an ordinary one- or two-solution form as follows : One-solution Sodium sulphite . 2 oz. zzo g.
Sodium carbonate . I „ tic) „ Para-amido-phenol . 55 grs. I 2 „ Water . . . io oz. 1,000 ccs.
The above is ready for use.
Two-solution A. Para-amido-phenol . too grs. 23 g.
Potass. metabisulphite 5o „ 11.5 „ Distilled water . . 10 oz. I,000 ccs.
B. Sodium sulphite . 30o grs. 69 g.
_Potass. carbonate . 300 „ 69 „ Water . . . ro oz. 1,000 ccs.
For use, mix r part of A with 2 parts of B. Para-amido-phenol developers are suitable for all makes of papers and they do not stain. Solutions keep good for a long time even in uncorked bottles.