120 
PRACTICAL PHOTO-MICROGRAPHY. 
The best results seem to be got with this developer 
when it takes about five minutes to fully develop a 
plate ; the contrast is then admirable, and if exposure 
has been sufficient the details are fully reproduced. 
The Metol Developer. 
A. 
B. 
C. 
Dissolve metol 
in water 
Add Sodium sulphite 
Potassium carbonate 
Water to 
Potassium bromide ... 
Water to 
Normal Developer : 
i part, or 50 grs. 
100 parts, or 10 ozs. 
10 parts or 1 oz. 
1 part, or 1 oz. 
10 parts, or 10 ozs. 
.5 parts, or -§■ oz. 
10 parts, or 10 ozs. 
A 1 part. 
B 3 parts. 
To each ounce of these mixed add 20 mins, of C. 
This solution'of metol (A.) keeps good for any time, 
and even the complete developing solution will keep 
for a long time, and may be used several times. Under 
this developer the image comes up much more rapidly 
than with the others. In fact, the beginner may be 
alarmed on first using this developer ; but, if time be 
given, due density will come, provided the plate is not 
greatly over or under-exposed, and the plate will hardly 
ever fog with metol. Where there is no great difficult)' in 
getting contrast, or where great contrast is not required, 
this reagent should certainly be tried carefully; if the 
developer is diluted the contrast is lessened ; bromide 
slows the action. Development may be started with a 
mere trace of alkali, and detail and density will still 
come after a time. Or we may develop in a “ tentative” 
way; beginning with little alkali, and when the image 
