MICROSCOPIC OBJECTS. 



15 



useful to add to the developer in case of 

 over-exposure. 



The developer which the writer prefers, 

 and which he has used successfully for all 

 sorts of work for some years, is the follow- 

 ing: 



A. — Pyrogallic acid, . . \ ounce. 



Sodic sulphite, . . i " 



Water, 40 ounces 



Citric acid, ... i dr. 



B. — Liquor ammonise, . \ ounce 



Potassic bromide, . 40 grains. 

 Water, 40 ounces. 



These form stock solutions, and will keep 

 indefinitely. Both had better be kept in 

 stoppered bottles. The sodic sulphite 

 must be good ; otherwise, good results 

 need not be expected. Some writers have 

 stated that sodic sulphite produces green 

 fog, but this is hardly correct. The writer 

 had used the sulphite developer for over 

 two years before he saw anything of green 

 fog. He had been accnsfoniird to buy his 

 chemicals from a good clieniist, and had al- 

 ways paid IS. 6d. per pound for sodic sul- 

 phite. Happening once to require some 

 immediately, he purchased a sample from 

 the nearest shop, and paid 6d. per pound 

 for it. It was wretched looking stuff, but 

 he made it up. On developing, every plate 

 was covered with a glorious sheen of green 

 fog. Happily, this was completely got rid 

 of by applying Mr. H. Farn»er's solution, 

 which will be described further on. Moral: 

 Buy the best chemicals from a good chemist, 

 and do not grudge the price paid for them. 



Another modification of the pyrogallic 

 developer is given by Mr. S. Fry, as fol- 

 lows : 



A, — Acid pyro., ... i ounce. 



Saturated acid solu- 

 tion of sodic sulphite, 12 ounces. 



B. — Ammonium bromide, 300 grains. 



Ammonise liquor, . 2 ounces. 

 Water, .... 12 ounces. 



Take i ounce of A ; put it in a 20-ounce 

 bottle, pouring on it 15 ounces of water. 

 Do the same with B. Use equal parts for 

 developing. 



To develope a plate, proceed as follows : 

 Have a good sized lamp glazed with pale 

 red glass, not with the black abomination 

 generally called "ruby," which is almost 

 opaque to light. A good lamp may be 

 made from any kind of box, by fitting to it 

 a sliding pane of red glass in place of the 

 lid, and putting a small parafiine lamp 

 therein. A chimney shDukl be made at the 

 top, to ventilate the box. This arrange- 

 ment will give a flood of light without en- 

 dangering the plate. The writer always 

 developes close up to the lamp, and has 

 never yet fogged a plate. If the operator 

 cannot see what he is doing, he need not 

 expect good negatives, but may reasonably 

 look for indications of failing eyesight after 

 a few months' work. So, to get good neg- 

 atives, and save temper and eyesight, have 

 plenty of light of the right sort. No light 

 is really non- actinic, and much of the 

 "ruby" glass in use is quite as unsafe to 

 use as the yellow glass used in developing 

 wet collodion plates. Yet, once in the de- 

 veloper, even yellow glass may be used with 

 complete safety. It is only while the plate 

 is dry that exposure to a strong light is 

 likely to act injuriously. Thus in changing 

 plates, or in taking them from the slides to 

 develope, let the lamp be shaded or turned 

 down ; but while developing, every detail 

 must be clearly seen. 



To proceed. Place the developing dish 

 near the lamp ; pour into the developing 

 cup, for a half pla-te, i ounce of the pyro 

 gallic solution, and i-ounce of the ammonia 

 and bromide. Place the plate in the dish, 

 and pour over it the mixed solutions. If 

 the image runs out rapidly, pour the devel- 

 oper off, and make up a fresh developer of 

 I ounce pyro. and i dram ammonia and 

 bromide. If, after this, the detail does not 

 come out satisfactorily, pour the developer 

 .back in the cup, and add more ammonia. 

 By varying this mode, plates that have re- 

 ceived thirty times the correct exp)sure 

 may be satisfactorily developed. They will 

 hardly h3,ve the brilliance an 1 "pluck" of 

 a properly exposed negative, but will yield 

 fair prints. 



If the image does not make its appear- 



