For some time past German photographers have been speak • ing very highly of the merits of solution of acid sodium sulphite as an addition to the fixing bath.

When pyrogallol was first used for dry-plate development. in conjunction with alkalies, several formulae were proposed using sodium sulphite as a preservative agent, and it was found that the addition of sulphurous acid had a very beneficial effect. This acid was added directly, as such, in solution, or it was developed in the mixture of pyrogallol and sodium sulphite by the subsequent addition of sulphuric acid, which caused the formation of a certain amount of sulphurous acid in the fluid, and at the expense of the sodium sulphite. No matter which method was employed, the final result was the formation of a small quantity of acid sodium sulphite, which preserved the pyrogallol for a much longer period than when ordinary sodium sulphite was used. But the trouble about these early efforts at preserving pyrogallol was that the quantity of acid sulphite present was small compared with the amount of ordinary sulphite. There is now made in a very convenient form a very strong solution of acid sodium sulphite, that in the compounding of developers will prove extremely useful. The material is in the form of a pale, yellowish fluid, smelling strongly of sulphurous oxide gas, with which it is saturated, and containing over 50 per cent, of acid sodium sulphite in solution.

That is to say, it contains half its weight of acid sodium sulphite, while ordinary sodium sulphite in crystals contains half its weight of normal or neutral sodium sulphite. From the nature of the two salts, the acid-sulphite solution contains, therefore, twice the amount of the preserving element, sulphurous oxide, which the ordinary-sulphite crystals contain. This would be true if the ordinary sulphite crystals were pure, but it is next to impossible to make them so, for they usually contain 4-6 per cent. of sodium sulphate, and 2-3 per cent. of sodium carbonate. The new acid-sulphite solution contains a little sodium sulphate, but the excess of sulphurous oxide gas with which the fluid is charged compensates for this. Such is the new material placed in the hands of the photographer. Now a few words as to its uses.

The first important application of the new fluid is in the fixing bath. If to a quart of fixing bath (one to four) we add about 2 oz. of acid-sulphite solution, the bath is rendered acid, but no change takes place otherwise. In this bath any negatives can be fixed, and with a rapidity and clearness that is really startling. Some of the slow varieties of plates are remarkably long in the ordinary bath before they are fixed nicely; but in the new acid-sulphite and hypo bath they fix in about one-fourth the time ordinarily taken. And what is yet more pleasant to note, they are remarkably clean and free from stain. In fact, they look exactly like plates developed with ferrous oxalate after they come out of the new bath, although they may be badly stained before fixing. The new fixing bath is beyond question the best remedy for stained plates from organic developers. One thing must certainly be remembered at all times, the fixing bath must be kept acid by the addition of new acid-sulphite solution from time to time in order to have it maintain its efficiency as a clearing bath.

If the proper care is exercised, the use of the alum clearing bath can be entirely omitted when the new acid-sulphite solution is used; thus eliminating a step in the present negative process when clear, crisp, and quick negatives are desired.

We must now say something about the application of the acid sulphite to the developer. With pyrogallol the application is very simple: to every grain of pyro in solution add one drop of the acid-sulphite solution as a preservative. Thus you may take: - Pyrogallol, 1 oz.; acid sulphite, 1 oz.; water to make 10 oz.

This solution contains 5 1/2 gr. of pyro to the fluid drachm, and will keep a long time. To develop: in 1 oz. of water use 1/2-1 fl. dr. of the above solution, with 1 1/2-2 fl. dr. of alkaline solution, made as follows: - Sodium carbonate (crystals), 5 oz.; water to make 10 oz.

In the case of eikonogen it works equally as well as with pyro. In this case the formula becomes: - Eikonogen (finely powdered), 1 dr.; acid sulphite, 1 dr. (fluid); water to make 10 oz.

Dissolve the eikonogen first, then add the acid sulphite. This solution contains 3/4 gr. of eikonogen to the fluid drachm, and keeps as well as the pyro mixture above. In developing, if sodium carbonate is used, to every ounce of the eikonogen solution add 1-2 dr. of the solution given above for pyro, and no water. If potassium carbonate is preferred, use 1-2 dr. of the following solution: - Potassium carbonate (dry), 3 oz.; water to make 10 oz.

In each case the negatives come up clear and full of detail, without any tendency to fogging. Judged by experience with the ordinary developers, these new mixtures with acid sulphite work a little more quickly; and if the negatives are fixed in the acid-sulphite fixing bath, the result leaves nothing to be desired as to quality.

With hydroquinone we have not yet obtained any desirable results, the mixtures tried working much too slowly to be of practical use.

As the developers given above work more rapidly than those ordinarily employed, care must be taken in regard to the light used in the dark room that it is of proper non actinic quality. It is best to use as little light as possible under any circumstances, but always enough to see what you are doing.

We are sure that those who use the new acid sodium sulphite will find it a great help to the production of clean, stainless negatives, closely resembling those of wet-plate days. - (Anthony's Bulletin.)