94 



THE AMERICAN MONTHLY 



[May, 



of the negative will disappear in this 

 solution, and when no more white is 

 visible when the plate is examined 

 from the back, it may be removed 

 from the solution, washed thoroughly 

 in water, and set on the rack to dry. 

 When dry the negative is ready for 

 use. It may be protected by a coat 

 of negative varnish, which is applied 

 by pouring it on the slightly warmed 

 plate held horizontal in the hand, 

 flowing it over every part and pour- 

 ing the excess off one corner back 

 into the bottle. Varnishing is not 

 necessary if the plates are used with 

 reasonable care, but it is strongly 

 advised for valuable negatives. 



Pyro development must be deferred 

 until next month, as well as instruc- 

 tions for treating plates not properly 

 exposed. 



FORMULAS. 



We have selected a few of the best 

 formulas, every one of which we can 

 recommend with the fullest confi- 

 dence. Get the chemicals from deal- 

 ers in photographic goods, for they 

 know what is required. 



The largest firms in New York are 

 The Scovill Manufacturing Com- 

 pany, 433 Broome st., and E. & H. 

 T. Anthony & Co., 591 Broadway. 

 They have many agents throughout 

 the country. IVIessrs. Walmsley & 

 Co., in Philadelphia, have everything 

 of the kind, and in Boston the Blair 

 Tourograph Company, T r e m o n t 

 street, do a large business in this line. 

 Send for their price-lists, and order 

 from them, as we ha^•e known several 

 instances when beginners have failed 

 in their work by using the wrong 

 cliemicals, which were purchased at 

 drug stores. 



Formula i . Ferrous Oxalate De- 

 veloper. 



A. Neutral Oxalate of Potash , Satu- 

 rated Solution. When dissolved, add 

 concentrated solution of oxalic acid 

 until a piece of blue litmus paper in 

 the solution turns red. Let sediment 

 settle, and pour otl'the clear liquid. 



B. Ferrous Sulphate (Copperas), 

 Saturated Solution. 



To each ounce of the solution add 

 about one drop of ordinary sulphuric 

 acid. Keep in a well corked bottle. 



For use, pour i part of b slowly 

 into 16 parts of A. The mixed de- 

 veloper is of a fine red color, and 

 should be perfectly clear. The pro- 

 portions given are for fine, soft nega- 

 tives. Most writers advise i to 8, 

 some go as far as i to 3. Those who 

 use such strong developers condemn 

 the ferrous oxalate, and say it gives 

 no control over the development. 

 Possibly, the fault is not in the de- 

 veloper. With such proportions we 

 should think not I Any developer 

 will give good pictures if properly 

 used. 



Formula 2. Restrainer. 



Potassium Bromide, saturated so- 

 lution in water. 



This restrainer can be used with 

 all developers. It is well to keep it 

 in a small-necked bottle with a drop- 

 ping tube, readv for immediate use. 



Formula 3. Dr. Eder's Normal 

 Developer. 



A. Neutral sulphite of 



soda, 2^ grammes. 



Sulphuric acid, S drops. 



Pyrogallic acitl, 12 grammes. 



Water. 100 c.c. 



B. Neutral sulphite of 



soda, 3^ grammes. 



Carbonate of pot- 

 ash, 90 "■ 

 Water, 200 c.c. 

 A gramme is equal to about 15.4 

 grains. 3^ cubic centimetres make 

 a fluid drachm. 28. 4 c.c. an ounce. 

 Foruseadd i partofAto20of water, 

 and I part of b to 30 of water, and 

 mix the solutions in equal parts. 



Formula 4. Allen & Rowell's De- 

 veloper. 



A. Water, 5 ounces. 

 Sulphuric acid, 30 drops. 

 Ammonium bromide, 60 grains. 

 Pvrogallic acid, ^ ounce. 



B. Water, 4 ounces. 

 Crystallized sul- 

 phite of soda, 360 grains. 



Potassium bromide, iSo '' 



