All these "wrinkles and dodges" in practice come in particularly good now as we are entering this new arena of practice, and if we would have abundant success, we must be on the alert for every sign and signal which comes from those who are more experienced than we, and who are so

I have become convinced that the method of adding the ammonia and bromide by degrees to the pyro is better than adding a nearly or full dose at once, and recommend the return to the use of the dropping - bottle where there is any doubt of the right exposure. To insure the right bottle being in its right place when wanted, I have devised what I call a "developing cruet,' and which any one can construct for themselves. I take four one-ounce wide-mouth bottles, such as the iodides and bromides come in, fit them with fine, smooth corks, long enough to enter the neck half an inch, and project about the same; prepare the corks by immersing them in melted paraffin for a few minutes, remove, and wipe off the excess; bore a hole through them that will allow one of the straight glass dropping - tubes, with rubber nipple, to be fitted to each, so as to reach within a quarter of an inch of the bottom, and your dropping-bottles are complete. To insure against their being misplaced when wanted, I arrange them on a base of wood 3 x 9 x 1/2 inches thick, with countersunk holes one-half inch apart to receive them; cement them in their places either with melted shellac or pitch, or thick varnish; letter each bottle with any black color that will not wash off, with letters to indicate their contents; then screw down the base in a position to be within easy reach of the developing trough. The cut will explain the "cruet" when finished. P contains concentrated pyro solution.

Fig. 88.

333 Pyrogallic Acid Developer 110

Pyro,....................................................................................

1 ounce.

Glycerin,.........................

1 "

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

3 ounces.

Alcohol,.........................

4 "

wood Naphtha,.........................

1 ounce.

A B contains ammonia and bromide..........................

Concentrated Ammonia,.........................

1 ounce.

Bromide of Ammonium,.........................

60 grains.

Glycerin,.........................

1 ounce.

B contains plain bromine..........................

Ammonium or PotassiumBromide,.........................

120 grains.

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

2 ounces.

A contains plain ammonia..........................

Concentrated Ammonia,.........................

1 ounce.

glycerin,.........................

1 "

The dropping - bottle need only be kept about half full for use, replenishing as occasion requires. In a glass-stoppered bottle mix one ounce of P with twenty-one ounces of water, and label pyro developer, which will be about two grains to the ounce. To develop a plate, generous as to give us the benefit of their experience. Indeed, it is as remarkable as it is commendable, to witness how very enthusiastically this promising process has been worked out to successful results, with the full determination on the part of the industrious ones to give all they know freely to the fraternity. So may it ever be.

say one of 5x 8 size, measure out three ounces of pyro developer, lay the plate in a shallow, black tray, and pour over it the plain pyro; into the measure drop three drops of A B, return the pyro to the measure and back over the plate; if in fifteen or twenty seconds the image appears, and that slowly, at once drop into the graduate three drops more of A B, and mix the developer with it as before, and return to the plate; if the plate has bad the right exposure it will continue to develop with an even pace, and when the shadows are just grayed over, stop developing, rinse off with cold water, and, if temperature is high, place in a saturated solution of alum tot from one to two minutes, then rinse and place in a fixing solution of hyposulphite of soda one part, and water six. When fixed, wash for about the same time as for a collodion negative, and again place in the alum solution for five minutes, to eliminate the hypo (I consider the credit is due Mr. John R. Clemons for suggesting the use of alum in photography as an eliminator of hypo); again wash and dry spontaneously. In case of a plate showing no indication of an image in half a minute, then, instead of adding more of A B, add the same number of drops of A, and a further addition if required, till five or six to each ounce of the developer has been added; if this fails to bring out an image, a very rare case indeed, then the plate is under-exposed. Again, over - exposure will be indicated if, on addition of one drop of A B to each ounce of developer, the image starts pretty rapidly in eight to ten seconds, in which case to each ounce of developer in the tray add five drops of P, and one to three drops of B, in one corner, and mix with the developer. These are the check-reins, so to say, to hold in check the over - exposure and permit a good negative to be obtained, that with a large dose of ammonia added at first would have been very difficult to secure. The foregoing mode of development is recommended principally for out - door exposures. For portraiture, where the light is more under control, two or three drops of A B may be added to each ounce of developer before flowing over the plate; and for known short exposure, five drops of A B may be mixed with each ounce of developer before flowing over the plate. - John Carbutt.

I have just tried a modified developer for gelatin plates after a formula given to me by Mr. R. Schlegel, and found it to work so well that I publish it here: Mix one ounce of the strongest liquid ammonia, one ounce of a solution of fifty grains of bromide of potassium in one ounce of water, and one ounce of eau de javelle ( this is a compound of one part each of chloride of lime and potash in five parts of water); add twenty grains of this solution to a solution of one grain of pyrogallic acid in 400 grains of water. The mixture develops a clear and intense negative, and a little over - exposure will not do so much harm as with other developers. It is now well known that an exposed gelatin plate will give a thinner negative if developed after some time than if developed at once. The latent image will keep for a longer time if the plate be dipped (and kept) in water after exposing. In some cases this may be found useful. - Dr. E. Liesegang.

Should the negative not develop vigorously, the development is forced by increasing the proportion of ammonia, or sometimes that of pyrogallic acid. Though promoting the appearance of tbe details, this often causes fogging, the negative remaining thin and weak It of ammonium at ten per cent. If the exposure has been too short, add to the developer, as. soon as possible, the half of the whole of its volume of ordinary water, then continue the development until all the details have appeared. This large addtion of water, which at first sight may appear rather strange, does certainly retard the development in a slight degree, but not as much as might be supposed before making the experiment However, it is absolutely necessary in order to prevent the hard-aning of the lights and to preserve all the harmony of the negative. It you wish , during the development, to increase the intensity of the nega-tive, as you have done in the case of the pyrogallic acid, add to the developer some more of the iron bath with a little of the bromide of ammonium. The same result is obtained; as has been said, by Mr. Kennett, in making this addition to the hyposulphite bath: but the trouble resulting from this in the fixing solution renders the first method preferable. To end this very important question of development, please let it be said that a concentrated solution of bisulphide of soda, which has remained for fifteen minutes in granulated zinc, and to which has been added after filtration a small quantity of pyrogallic acid in crystals, forms an excellent developer for gelatino - bromide plates. The use of granulated zinc is not indispensable.