DEVELOPMENT OF THE PLATE. Iig 
both detail and density, then we add water to the 
developer, and then ammonia. (This reduces the pro¬ 
portions of bromide and pyro, and increases that of the 
alkali.) Broadly speaking, pyro gives density, alkali 
gives detail, and bromide restrains the action of both. 
The Hydrokinone Developer. 
A. Take hydrokinone ... ... ... ... 80 grains. 
Potass, jmetabisulphite ... ... ... 40 ,, 
Potassium bromide ... ... ... ... 15 ,, 
Water to .. ... . ..10 ounces. 
B. Take potassium hyd rate -^ 11 caustic potash ” 80 grains. 
Water, distilled and boiled ... ... ... 10 ounces. 
A suitable developer will be found to consist of one 
part of A, one of B, and one of water. 
With this developer the details will not come up so 
quickly as with the last, but the action will not die 
away so soon ; and one dose of this developer may be 
used at least four times, i.e., for four plates, though 
we do not recommend this practice. If after two are 
developed the action seems to become slower, a small 
addition of the alkali may be made. And we generally 
add less than one part of water; thus, we take half an 
ounce of A, the same of B, and we make up with water 
to 10 drams only instead of 12. It may be found 
difficult to keep the caustic alkali in solution energetic 
for any length of time, as it becomes carbonated ; the 
plan is to boil the water for solution, and to keep the 
solution in several small bottles full to the top and well 
stoppered. And we buy the alkali in small quantities, 
as it keeps badly even in the solid state. 
