PHOTOGRAPHIC OUTFIT 17 



tage be placed in a weak alkali bath for as much as 

 half an hour before development, and then developed 

 slowly with a rather weak developer. 



If a plate is too dense, it may be reduced, after 

 being thoroughly washed, by putting it in a bath 

 containing about three per cent, of persulphate of 

 ammonia, then thoroughly washed. A plate that is 

 too thin but has detail may be improved by intensify- 

 ing; but an under-exposed plate having strong high 

 lights and transparent shadows should be reduced 

 rather than intensified. A good bath is made of a 

 saturated solution of bichloride of mercury. When 

 thoroughly whitened, rinse the plate and blacken it 

 in a weak bath of aqua ammonia or sulphite of soda. 

 The plate must be free from all trace of hypo, other- 

 wise there will be yellow stains or irregular intensi- 

 fication. 



In all cases be sure to dust your plates carefully 

 before placing them in the tray. Wash the plates 

 thoroughly before fixing, and fix with fresh hypo 

 bath, except when the weather is hot ; then the 

 acid fixing-bath recommended by the Cramer plate- 

 makers should be used. It hardens the film and 

 keeps well, and allows of any after treatment that 

 may be necessary for the plate. Another good hard- 

 ener is formaline (i part to 16 of water). This may 

 be used either before or after fixing. Its keeping 

 qualities are good, and it may be used repeatedly, 



