138. The desire for greater rapidity has been one largely in the minds of photographers always. This is all right enough, so long as good qualities and necessary ones in the negative are not sacrificed. Sometimes they are. During the past two or three years, many "quick" processes have been published, but in result they are never superior, and often inferior, to what is obtained by the usual photographer by ordinary means. It is an acceptable thing to the sitter to be released a few seconds sooner from the grip of the head-tongs, but it is no honor to the artist if his results are spoiled.

138. To ninety-six ounces of pure water add eight ounces of nitrate of silver, forty grains of iodide of potassium, and two hundred and eighty-eight grains of nitrate of baryta. Shake until the whole is dissolved. Now filter thoroughly through two thicknesses of filter - paper; filter several times until the milkiness has all disappeared, then make sufficiently acid with C. P. nitric acid. Any good developer will do, hut I make mine in this way:

Pure Crystels of Iron,....................

10 ounces.

Granualted White Sugar,................

. 6 "

Water,........

. 32 "

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

. 3 "

Of this stock solution take three ounces, and add twelve ounces of water and one ounce of acetic acid.

I have been able to make pictures of infants in one second, that were full-timed negatives, and averaged sittings in from three to six seconds. - E. P. Libby.

Rapid negative bath:

Nitrate of Silver,................

35 grains

Boric Acid,................

. 4 "

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

1 ounce.

Iodide of Potassium, quantum sufficit.

A few drops of nitric acid, sufficient to render the bath slightly acid. Developer:

Sulphate of Iron,................

29 grains.

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

20 drops.

Acetate of Lead (sugar of Lead)................

3 grains.

Water,.........

1 ounce.

Put a filter in a clean funnel, and fill it a quarter full with boric acid, filter the developes always through it; the solution will take up the necessary quantity of boric acid; the filter and boric acid will last a very long time. - Alexander Henderson.

For extra rapid work try the following:

Nitrate of Silver,................

8 ounces.

Iodide of Sodium,................

40 grains.

Nitrate of Baryta,................

.....288 "

Distilled Water,................

96 ounces.

Conrad Peterson. I do not believe in this "lightning" business. I can produce as "quick " results as any of you with my ordinary solutions. - Old Argentum.

The Developer.- The collodion may flow never so smoothly, and the nitrate solution prove ever so sesitive, yet they are powerless to produce results, onless a third solution known as the developer be employed. It startles the latent image from its shumbers within the film, as the sunshine startles the morning and develops it into the perfect day" The development of a photographic plate is probably the most beatiful operation in chemistry or physics. Once the developer strikes the ex-posed film armies of molecules are started into action, and move in solid phalanxes as well as in tiny squads, with one intent, to build up the grand result To make the developer, haveastock - bottle containing

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

64 ounces.

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

4 "

From this separate Fourteen ounces, and add thereto two ounces of acetic acid. Shake well

I wish here to confine myself to showing how a rapid negative bath may be made that will keep in working order for an indefinite period, with only the usual strengthening and occasional boiling to get rid of the ether and alcohol. Formula for bath:

Nitrate of Silver,...............................................................

2 1/2 ounces.

Common Water,.............................

30 "

Nitrate of Barytes,.............................

90 grains.

Iodide of Potassium,.............................

20 grains

Nitric Acid.....................................

Enough to (how slight acidity.

filter, and the bath is ready for use.

The filtering-paper containing the undissolved iodide of silver must not be thrown away, but used every time the bath is filtered. To obtain the full effects of this bath, it is necessary to have an excess of iodide of silver. When the bath requires strengthening, add three grains of barytes to each ounce of solution in addition to the nitrate of silver, otherwise it would be difficult to estimate the strength of silver in the bath. By the argentometer this bath will register about thirty-five degrees. Any collodion will do; it must not be too horny. - W. E. Debenham.