PHOTOMICROGRAPHS AND LANTERN SLIDES 
155 
expose fully, but do not overexpose, and develop until the image 
shows plainly on the back of the plate. In such cases, the usual 
developers will not give as good results as a developer modified to 
give dead blacks upon a perfectly transparent background. For 
this purpose, Dr. Land’s formula is the best we have tried. 
Land’s Contrast Developer.—- 
Hydrokinon. 20 g. 
Sodium sulphite (dry). 60 g. 
Sodium carbonate (dry). 140 g. 
Potassium bromide. 12 g. 
Water. 1,000 c.c. 
If kept tightly stoppered, with no air space between the liquid 
and the cork, this developer keeps almost indefinitely. When 
some is taken out for use, the rest should be put into a smaller bottle, 
so that there shall be no air between the liquid and the cork. 
Another formula, developed by Dr. Land to meet the trying 
conditions of the tropics, is also useful for lantern slides. 
Land’s Tropical Developer.— 
Hydrokinon. 
Metol. 
Sodium sulphite (dry). 
Sodium carbonate (dry) 
Potassium bromide. 
Water. 
. 8 g. 
. 3 g. 
. 30 g. 
(60 g. if crystals are used) 
. 30 g. 
(90 g. if crystals are used) 
. 2 g. 
. 1,000 c.c. 
This formula will develop an underexposed plate when the usual 
developers fail. With this developer, the image flashes into sight 
with surprising suddenness, but do npt become startled and remove 
the slide too soon, lest you fail to secure details. 
It is not necessary to furnish the usual formulas for developers 
and fixing solutions, since these are furnished with every box of plates. 
We have found the Cramer plates very satisfactory for all kinds of 
photographic work. The firm will send gratis to anyone who requests 
it Cramer’s manual on Negative-making and Formulas (G. Cramer 
Dry Plate Co., St. Louis, Mo.). 
