AMATEUR PHOTOGRAPHY. 393 
water, as it is important to free it from 
hypo before attempting to intensify it. Let 
it wash for half an hour, by which time the 
bleaching solution will have dissolved 
ready for use. Place the negative in this 
solution, and it will at once begin to turn 
milky white. 
Leave it in the solution until it is white 
clear through to the back. There is no 
danger of overdoing this part of the opera- 
tion, and a few minutes more or less will 
make little difference in the result. When 
the plate is thoroughly bleached pour off 
the bleaching solution and keep it for fu- 
ture use. Wash the bleached negative thor- 
oughly for half an hour at least, and in the 
meantime make up a solution of sodium 
sulphite, about 20 grains to an ounce of 
water. Having given the bleached negative 
a thorough washing, place it in the sulphite 
solution, and it will immediately begin to 
turn brownish black. As soon as the black- 
ening process is complete pour off the soda 
solution and give the negative another half 
hour’s wash. The whole negative will have 
become thicker and the color changed to a 
warm brown black, and the negative will 
print much slower than before. The print 
will show decidedly more snap and con- 
trast than those previously made. The 
whole process may be repeated if the first 
trial fails to give satisfactory results, al- 
ways being careful to give the negative a 
thorough washing between the operations. 
There are other methods of intensification 
which may easily be tried, but the foregoing 
is probably as satisfactory as any for the 
amateur. Intensification is of value only 
when there is detail in the negative to work 
on. On under exposed negatives which are 
thin but which lack detail in the shadows 
it is disappointing, for it only adds con- 
trast, but can not bring out detail which 
does not exist. It really makes the nega- 
tive worse instead of showing improve- 
ment. It is almost impossible to make any 
improvement in badly under exposed nega- 
tives, and the best course is to throw them 
away. 
For negatives which are thin from over 
exposure simple intensification is probably 
the best means of improvement. Some over 
exposed negatives, in which development 
has been prolonged in the attempt to gain 
contrast, are thick and heavy looking, slow 
in printing, and yield flat, washed out prints. 
On these it is best to perform a sort of 
compound operation, first removing some of 
the extra. density with a suitable reducing 
agent, and then, if the prints still lack con- 
trast, intensifying the negative as previ- 
ously described. 
As with intensification there are various 
methods for reducing a negative, but the 
best one is that known as Farmer’s method, 
which makes use of a solution of red prus- 
siate of potash and hypo. To prepare it 
weigh out 4% ounce of hypo and dissolve it 
in 4 ounces of water. In another bottle 
or graduate dissolve ferricyanide of potash 
(red prussiate of potash), 40 grains in one 
ounce of water. This should be done in a 
weak light, as light causes a chemical 
change to take place in the ferricyanide. For 
the same reason the operation of reducing 
should be performed in a dim light. 
To use the solution, add a few drops 
of the ferricyanide solution to the hypo 
and pour it over the negative, which has 
previously been well soaked to soften the 
film. It is advisable to give the negative 
this preliminary soaking before subjecting 
it to the action of any chemical solution, in 
order that the action of the solution may 
be uniform. The negative should be 
watched closely, and if it does not begin to 
lose density in a few minutes, add a few 
more drops of the ferricyanide solution, the 
rapidity of action depending on the quantity 
of this chemical in the solution. It is bet- 
ter to use a rather weak solution, as its ac- 
tion is more likely to be even and can be 
more easily controlled, but at the same 
time too long soaking in the bath may 
stain the negative yellow. 
After a few trials you will learn how the 
operation should proceed, and will mix 
your solutions accordingly. Keep a close 
watch on the negative, and as soon as it 
appears thin enough give it a thorough 
washing, for half an hour at least. If, on 
making a trial print after the negative has 
dried, it still lacks contrast, intensify it as 
already explained, and in all probability it 
will show great improvement. The action 
of Farmer’s reducer on a plate is like that 
of a carpenter's plane on a board. It 
takes off an even layer from the whole sur- 
face, changing the relative densities of the 
different parts little, but slightly increasing 
the contrast. For harsh, under exposed and 
contrasty negatives a reducer of the oppo- 
site sort is needed, one that will take hold 
of the dense portions, while acting slightly 
on the thin parts. It is only within the last 
few years that a reducer of this character 
has been known, but at the present time we 
have an excellent article for this purpose, 
known as ammonium persulphate. It can 
be bought at any photographic supply store 
for about 20 cents an ounce, an ounce being 
sufficient for dozens of negatives. To use 
it, dissolve 30 grains in 3 ounces of water. 
Prepare also a solution of sodium sulphate, 
say 75 grains to an ounce of water, which 
is practically a 10 per cent solution. Give 
the faulty negative a good preliminary wash- 
ing and then place it in the reducer. Re- 
duction begins at once and must be care- 
fully watched. Just before the right point 
