_Sir W. Newton's Process._--Having been requested by several friends to
give them a statement of my mode of proceeding with reference to the
calotypic art, and as I am of opinion that we ought to assist each other as
much as possible in the pursuit of this important branch of photography, I
beg therefore to offer the following for insertion in your "N. & Q.," if
you should deem them worth your acceptance.
_To iodize the Paper._--1st. Brush your paper over with muriate of barytes
(half an ounce, dissolved in nearly a wine-bottle of distilled water): lay
it flat to dry. 2nd. Dissolve sixty grains of nitrate of silver in about an
ounce of distilled water. Ditto sixty grains of iodide of potassium in
another bottle with the like quantity of water. Mix them together and shake
well: let it subside: pour off the water, and then add _hot_ water: shake
it well: let subside: pour off the water, and then add three ounces of
distilled water, and afterwards as much iodide of potassium as will
redissolve the iodide of silver.
Brush your previously prepared paper well with this, and let dry; then
place them in water, one by one, for about one hour and a half or two
hours, _constantly agitating the water_. As many as a dozen pieces may be
put into the water, one after the other, taking care that there are no
air-bubbles: take them out, and pin to the edge of a board at one corner.
When dry they will be ready for exciting for the camera by the following
process:
(These are supposed to be in six 1-ounce bottles with glass stoppers.)
+-------------------+--------------------+--------------+
| 1. | 2. | 3. |
| 1 drachm of No. | 20 min. of No. 3., | A saturated |
| 4., 6 drachms of | 6 drachms of | solution of |
| distilled water. | distilled water. | gallic acid. |
+-------------------+----------------+---+--------------+
| 4. | 5. | 6. |
| 25 grains of | 2 drachms of | Equal parts of |
| nitrate of silver | No. 4., 6 drs. | Nos. 1. and 2. |
| to half an ounce | of water. | |
| of water. Add 45 | | N.B.--This must |
| minims of glacial | | be mixed just |
| acetic acid. | | before using, |
| | | and the bottle |
| | | cleaned |
| | | afterwards. |
+-------------------+----------------+------------------+
_To excite for the Camera._--Mix equal parts of Nos. 1. and 2., and with a
glass rod excite the iodized paper and blot off; and it may be put in the
slide at once, or the number you require may be excited, and put into a
blotting paper book, one between each leaf, and allowed to remain until
required to be placed in the slide.
_Time of Exposure._--The time varies from three minutes to a quarter of an
hour, according to the nature of the subject and the power of the sun; but
five minutes is _generally_ the proper time.
_To bring out._--Bring out with No. 3., and when the subject begins to
appear, add No. 5.; and when sufficiently developed hold it up, and pour
water upon it; and then put it into hyposulphite of soda to fix it, for
about half an hour {141} or more, and then into water: this is merely to
fix it for the after process at your leisure.
_To clean the Negative._--Get a zinc tray about three or four inches deep,
with another tray to fit in at the top, about one inch deep; fill the lower
tray with boiling water, so that the upper tray may touch the water; put
your solution of hyposulphite of soda, not strong, in the upper tray, and
then your negatives one by one, watching them with care until the iodine is
removed; then put them in hot water, containing a small piece of common
soda (the size of a nutmeg to about two quarts of water), for about ten
minutes; pour off the dirty water, and then add more hot water, shaking
them gently for a short time; pour off the water again, and then add fresh
hot water, and let it remain until it is cold, after which take them out
CAREFULLY, one by one, and put them in clean cold water for an hour or two;
then take them _all out together_, and hold up to drain for a short time,
and then put them between three or four thicknesses of linen, and press as
much of the water out as you can; then _carefully_ (_for now all the size
is removed_) lay them out flat upon linen to dry.
_Mode of Waxing the Negatives._--Melt the pure white wax over a lamp of
moderate heat, just merely to keep it in a liquid state; then fill the same
deep tray as above described with boiling water, and with _another_ similar
to the upper one before described (_which must be kept for this purpose
only_); put a clean piece of blotting-paper in this tray, and lay your
negative _face downwards_, and with a soft _flat_ hog's hair-brush, about
an inch wide, dip it into the liquid wax, and brush the negative over, when
it will be immediately transparent, and it can be done so that there is
very little redundant wax, after which it may be put between two or three
thicknesses of blotting-paper and ironed, if necessary, which, however,
should not be _very_ hot, when it is ready to take positives from.
_Positives on Negative Paper._--Take one part of the iodide of silver
before described, and add two parts of water; then add as much iodide of
potassium as will redissolve it. Brush your paper with the foregoing, let
dry, put into water, and proceed, in all respects, as above described for
the negatives.
_Excite for Positives._--Excite with No. 1.; blot off: lay it in your
press, place the negative face downwards: expose to the light from ten
seconds to half a minute, or more, according to the light (_not in the
sun_), and bring out with No. 3.; and when it is nearly developed add No.
1.; then take it up and pour water upon it, and then place it in
hyposulphite of soda (cold) until the iodine is removed; after which put it
into allum water, about half a teaspoonful of powdered allum in two quarts
of water; this will readily remove the hyposulphite, and also fix the
positive more particularly; it will also take away any impurities which
there may be in the paper, after which put it into clean cold water, and
change two or three times.
I have been thus particular in describing the process which I have adopted,
more especially for beginners; and with great cleanliness and care in each
process, and especially in keeping all the bottles with the chemicals free
from dirt of every kind, the foregoing will lead to favourable results.