406 



RECREATION. 



paper, as used for binding lantern slides. 

 Another frequent source of fogging arises 

 from the blacking being worn off the in- 

 side of the camera and lens tube. This 

 should be renewed at least once a year. 

 An excellent dead black suitable for coat- 

 ing the inside of the camera and lens can 

 be made as follows : Dissolve shellac in 

 methylated spirit, and add dry lampblack 

 till the mixture is the consistency of thin 

 cream. It should be applied with a small 

 camel's hair brush. Too much shellac must 

 not be used, or the black will dry with a 

 polish. Other sources for fogging are : 

 White light getting in the dark room, and 

 the ruby lamp not being safe. These may 

 be tested by placing a plate in the dark 

 slide and drawing the shutter half way, 

 thus leaving part of the plate exposed. If 

 on developing the plate there is a differ- 

 ence between the 2 parts, either the lamp 

 or the room will be found at fault. A good 

 plan is to have a strip of red flannel tacked 

 all round the edge of the door. This will 

 keep out both light and draughts. 



Plates that have been fogged may be 

 cleared by placing them in a slow acting 

 reducing solution. A good formula is : 



Sulphuric acid V-/ 2 scr. 



Hyposulphite of soda 8 o-zs. 



Sulphite of soda 1 oz. 



Chrome alum 3 drm. 



Warm water 31 ozs. 



Dissolve the hyposulphite of soda in 14 

 ounces of the water, the sulphite of soda 

 in 3 ounces of water, mix the sulphuric acid 

 with 2 ounces of water and pour slowly 

 into the sulphite of soda solution ; add the 

 hyposulphite, and then dissolve the chrome 

 alum in 8 ounces of water, and add to the 

 rest. The solution, when cold, is ready for 

 use. The fogged negative should be placed 

 in this solution, and left until the shadows 

 are clear. It should then be taken out and 

 washed. 



Another good formula, which is also a 

 reducer, is known as Belitzski's green re- 

 ducer : 



Potassium ferric oxalate 2}/ 2 drms. 



Water 7 ozs. 



When this is dissolved, add crystallized 

 neutral sulphite of sodium, 2 drams ; oxalic 

 acid, 40 grains; hyposulphite of soda, i T / 2 

 ounces. This reducer must be kept in the 

 dark, as the light affects it. If kept well 

 corked, it will keep a long time, and may 

 be used over and over until exhausted. 

 The negative must be kept in this until 

 clear, then removed and washed. Green, 

 yellow, and red fog must be treated differ- 

 ently. Reduction will not touch the fog, as 

 it is caused by a peculiar condition of the 

 reduced silver ; therefore it is advisable to 

 change this latter into silver bromide, and 

 develop it. The negative to be treated for 

 colored fog should be placed in a dish of 



clean water, to thoroughly soften the film, 

 then place in 



Bromide of soda 1 drm., 15 grs. 



Bromine 2 scrs., 5 grs. 



Water 3^ ozs. 



When thoroughly mixed, place the nega- 

 tive in the dish, film side up, pour the 

 solution over and rock well. This must be 

 done in the open air, as the fumes from it 

 are obnoxious. The negative should re- 

 main in' this bath until it is white right 

 through to the glass side. It should then 

 be well washed and developed with a hy- 

 droquinone developer. A good formula is : 

 A. — Hydroquinone 1 drm. 



Sulphite of soda 4 drms. 



Acetic acid iy 2 drms. 



Water 5 ozs. 



B. — Carbonate of potassium 2 drms. 



Water 2 l / 2 ozs. 



For use, take 2 ounces of A and one 

 ounce of B. The development should be 

 carried on until the shadows are clear and 

 the negative appears black or • gray black 

 by transmitted light. The negative must 

 then be washed about 2 hours. If after de- 

 veloping, the negative shows signs of frill- 

 ing, it should be immediately immersed in 

 a weak solution of chrome alum for a few 

 minutes, which will have the effect of hard- 

 ening the film. Green fog may be removed 

 by placing the negative in a weak solution 

 of ferric chloride (perchloride of iron) 

 until the negative is bleached ; then place 

 in a dilute solution of oxalic acid, wash 

 well, and redevelop with the above devel- 

 oper. Another formula, slightly different 

 from the above, is to bleach the negative 

 in a mixture of equal parts of potassium 

 bromide (20 grains to the ounce) and ferric 

 chlorine (20 grains to the ounce), wash, 

 and then develop with ferrous oxalate de- 

 veloper. 



Yellow fog can be easily removed by the 

 following thiosinamin formula : 



Thiosinamin 5 drms. 



Citric acid 2]/ 2 drms. 



Water 1 qt. 



The negative should be placed in the 

 above, and allowed to remain until all trace 

 of yellow is removed, and then well 

 washed. If a piece of blue glass is placed 

 in front of a yellow negative while printing, 

 the resulting green light will give better 

 prints than the yellow alone. 



Harshness of negatives is another defect 

 which gives the photographer a lot of 

 trouble. It is usually caused by under 

 exposure, and consists of dense high lights, 

 clear shadows and but little half tones. 

 Negatives that are harsh give prints that 

 are very black and white, and are usually 

 known as the chalk and soot process. 

 These negatives may be modified by a great 

 number of methods, so as to give more 



