98 PRACTICAL PHOTOMICROGRAPHY. 



every three grains or one minim of alkali in the developer, 

 from two to four grains of sodic or potassic, or sodic and potassic, 

 citrate. (See page 62.) This immediately stops all further 

 development of detail, but does not seem to affect density which 

 is gained as follows : Add to the original developer, or to a 

 freshly made one, two to four grains of citrate for each minim 

 of ammonia or for every three grains of carbonate, pour away 

 the water and citrate on the plate and apply the modified de- 

 veloper for a minute or two. Then add to the developer a 

 brisk dose of alkali, say two minims of ammonia, and continue 

 development till sufficient density is attained. 



The carbonates may be restrained so easily and so forcibly with 

 bromide, that perhaps the simplest way when developing with 

 them is to add (say) one grain of bromide for each ounce of 

 developer. Water alone added to the carbonate developer 

 sometimes suffices to overcome moderate overexposure. 



"When the subject dealt with is by nature wanting in con- 

 trast it will be found useful to develop with an ordinary de- 

 veloper until all detail is up, and then to add citrate to the de- 

 veloper finishing as above with the brisk dose of ammonia. 



The citrate was suggested by Mr. Watmouth Webster, now 

 of Chester, Eng., and from its action 'in stopping detail but 

 not density in development will be found very useful. 



We have in this chapter formulated for one ounce of devel- 

 oper only ; this quantity will develop a quarter-plate ; two 

 ounces a half -plate or 7x5, four ounces a 10x8 plate ; but the 

 the beginner is advised to double these quantities till he has 

 become adept in evenly and quickly flooding his plate. 



During development the plate should be constantly shielded 

 from light even of the non-actinic lamp, being uncovered 

 only at the time and for the purpose of scrutiny. 



It may be well to recapitulate certain points of this chapter 

 referring to certain appearances shown by a plate soon after 

 the image has started to appear in the developer, normal as 

 on pages 91 and 92. 



Refusal to appear for one minute, or appearance in highest 

 lights only, bespeaks utter underexposure. 



High lights grey, shadows wanting severe underexposure. 



