232 PRACTICAL PHOTO-MlCBOGRAPHY 



where particularly hard contrast is desired, then from five to 

 ten drops of this solution may be added to each ounce of 

 developer. 



For lantern-slides or bromide-printing, solution No. 3 may 

 be substituted, and in this case equal parts should be taken of 

 solutions Nos. 2 and 3. But this will be referred to again 

 later when treating these particular subjects. All these 

 solutions keep well for at least some months ; but they should 

 in any case be kept in well-stoppered or well-corked bottles. 

 It is better not to make up a larger amount of solution than is 

 likely to be used in the course of a month or two. 



In cases where a negative is apparently over-exposed, the 

 amount of solution No. 1 may be increased, and that of solution 

 No. 2 decreased somewhat ; and the reverse applies in cases of 

 under-exposure, No. 2 then being in excess, and No. 1 somewhat 

 reduced. In cold weather these solutions will be found to 

 act considerably more slowly than in hot ; in fact, when the 

 temperature is low it will generally be found advisable to have 

 a somewhat more energetic developer, as the developing 

 action, apart from its speed, appears to be somewhat retarded. 

 The metol-hydrokinone formula may also be used for negative 

 development, and in cases where softness of gradation and full 

 detail is required, it will be found quite suitable. 



When development is completed, the plate should be 

 washed for a few minutes under the tap, and then immersed in 

 a fixing solution composed of 200 grammes hyposulphite of soda, 

 and water to 1000 c.c. The exact strength of this solution is 

 immaterial ; but the plate should be allowed to remain in it 

 until all whiteness, as seen from the back of the plate, com- 

 pletely disappears. A fresh solution should be used for each 

 batch of plates, and it is better to leave the plate in the solution 

 for several minutes after apparent complete fixation to ensure 

 that no unaltered silver remains in the film. Incomplete 

 fixation is sure to result in the appearance of markings on the 

 plates at a later stage, or to cause some general deterioration. 



After fixation is completed, the plate should be washed 

 thoroughly in running water for about an hour, and if washing 

 is carried out efficiently this time will suffice. The plate may 

 then be placed on edge or in a suitable rack to dry, and this 

 should be done in a place as free from dust as possible. 



