16 NATURE AND THE CAMERA 



such developer may be used with advantage, especially 

 in hot weather. 



In developing a plate, one should always keep it 

 under control and watch it carefully, so that it may 

 be removed when the proper density is reached. 

 Under-exposed plates need less acid and more water, 

 and over-exposed plates require less alkali, a stronger 

 developer, and a small quantity of restrainer, such as 

 bromide of potassium -(ordinary salt will do in an 

 emergency). With a plate correctly timed the 

 quality may be regulated by the relative proportion 

 of the ingredients. Thus when the developer is 

 weak in alkali or over-strong in acid, the plate will 

 give the effect of under-exposure, i.e., will be hard, 

 with decided contrasts and little detail in the shad- 

 ows; whereas, if the proportions were reversed, so 

 that the alkali predominates, the plate would be flat, 

 lacking contrasts, as in the case of over-exposure. A 

 very weak developer will have the same effect. 



A much over-exposed plate may be saved by being 

 placed in a bath containing a small quantity of re- 

 strainer and the developing acid, no alkali being 

 used. This bath should be kept in constant motion, 

 or else the plate will have irregular, wave-like mark- 

 ings. When removed from this bath, replace the 

 plate in the ordinary developer, containing some re- 

 strainer, and carry the development much further 

 than usual. Under-exposed plates may with advan- 



