Development. Photographers who aim at good work, and at ease in getting through it, are recommended to use a saturated solution of iron for the;r developer. It saves a great deal of time in making up solutions, and a great deal of trouble in weighing, shaking, et. and the strength of the developer can be altered at pleasure to suit the particular subject in hand. To use it. take

Saturated Solution of Iron,..........................................................

l 1/2ounce.

Glacial Acetic Acid..........

8 drachms..

Water..........................................................

18 ounces

This gives a fifteen - grain developer, To make a twenty - grain developer, take

Saturated Solution of Iron,..........................................................

3 ounces.

Glacial Acetic Acid,..........................................................

6 drachms.

Water,..........................................................

18 ounces.

W. T. Wilkinson.

140. It will be seen that there is diversity of opinion here also. The real fact is development, like exposure, is a matter of inspiration or of feeling. It is the department of manipulation above all others which requires the most careful watching, the most attentive thinking, and the clearest - headed handling. It is the file by means of which all the roughness of previous manipulations may be smoothed down and modified tolerably, if the head and hand help it. The simile is a mechanical one, but proper development is an art, or mayhap, a science.

I like the following:

Protosulphate of Iron,...................................................

2 drachms.

Common Alum,.....................................................................................

4 "

Acetic Acid.....................................................................................

2 "

Gum Camphor, broken up in small pieces in a bottle of water, ..................

6 ounces.

If the hath be stronger or weaker than thirty grains, the alum must be increased or decreased in the same ratio. - A. L. Henderson.

"We want to produce a negative brilliant in contrast, transparent, and solid. First, let us make a developer.

Iron,......................................................................................................

2 parts.

Epsom Salts......................................................................................................

1 part.

Acetic Acid,.....................................................................................

1 "

Hydrometrical test - Iron, fifteen grains.

This I consider the most perfect combination for a developer, as the astringent Epsom Baits reduce softly. Then there must be the proper amount of acid in the iron to insure a slow and continued deposit. Of course, a continued deposit depends mainly upon the condition of the bath, which must not be too acid. - S. P. Wells.

140. I offer a method of modifying the plain iron developer which shall produce any desired effect in ordinary gallery work, both positive and negative, and which will be found, for cheapness and convenience the best thing out.

The basis of stock solution of this developer is that used by a majority of photographers, viz.:

Water,....................................................................

64 ounces, fluid.

Protosulphate of Iron,...................................................

4 " by weight.

Acetic Acid,No.8,...................................................

4 " fluid.

If the silver solution has been in use for a length of time, it will be necessary to add from one to four ounces of alcohol to the above, which is to counteract the effect of the alcohol and ether, which may have accumulated in the silver solution from the collodionized plates.

The process of development by this solution should be carried on over a large glass funnel, which should receive all the solution which runs off the plate and the draining of the plate after development. This surplus or wash should pass through a loose filter into a receptacle below, and saved to be used again in the proportions of two-thirds of old to one-third new for positives, and for negatives in proportions to suit the purpose, but usually a greater proportion of the new to the old.

141. For delicate effects, preference is often given to the ammonio-sul--phate of iron developer. If your subject is dressed in white draperies or is himself fair- skined and fair- haired, this form will be found of service to you. Make it as follows:

Double Sulphate of Iron and Ammonia, ..................

2 1/2 ounces.

Acetic Acid, No. 8.......

5 "

Water, .......................................................... .......

40 "

Apply with the same care as the other. of a negative may be improved by intensification. After the first, or iron development, wash the - negative thoroughly all over, and then flow with the following solution:

Now by the above method any desired effect can be secured both in negatives and in positives,and it only requires a short experience by an observing operator to determine the proper proportions. It will also be observed that this formula, or rather method of development, has the great advantage of economy, reducing the expense of material for developing solution one - half ordinarily, in very few instances more or leas, as the work may be in positives or negatives.

In the development of a negative, if it is desired to obtain a very soft effect with fine definition, increase the quantity of new solution up to the exclusion of the old, as the case may be; to secure intensity, the proportion of old may be increased. It will at once be seen what a range of modifications is here obtained, and what great advantages may accrue from so simple a device. - E. M. EstahrookE.

141. My preference has always been for the ammonio - sulphate of iron developer. Make a saturated solution of ammonio-sulphate of iron in water, filter, and to every ounce of solution add one drachm of glacial acetic acid. This is a stock-bottle, and by making six or eight ounces, it will be sufficient for a large number of plates, and has the advantage keeping any length of time in good condition. Before developing a plate, it is necessary to reduce the strength of the saturated solution. Take a small wide - mouthed bottle, and to every five drachms of water add two drachms of the stock solution. The developer is now ready for use. Time may be saved by marking with a file or diamond upon the bottle the exact amount of water desired, and another mark for the iron solution. The proportion of five to two is the formula that I generally prefer, hut it can readily be altered to suit the subject by increasing or decreasing the amount of iron. When the bath is new no difficulty will be experienced in flowing the developer evenly over the plate, but by constant use, alcohol and ether being absorbed into it, the developer may require the addition of a little alcohol to make the solution run perfectly even. After standing for some hours a crystallization will take place in the bottom of the botth, but that is to be expected, and will do no harm to the solution. I have had no experience with this developer for portraits.

Negatives developed by this double salt are peculiarly suited for making glass positives for the magic lantern, also for solar enlargement. Indeed, for every purpose that I have used it (expect instantaneous photography), perfect satisfaction has been given. The concentrated character of this developer makes it well suited for out-door work, where every pound, additional weight is to be avoided by the operator. It is, of course, necessary to use as pure water as can be readily found for diluting the strength of the developer. Water containing chlorides in considerable proportions must be avoided. The time of exposure requires to be rather longer when this developer is used. - J. C. Browne.