59. Caution

Caution. All chemicals used for the sizing and salting must be absolutely pure. As ammonium chloride often comes in an impure state, special care must be exercised when purchasing it.

60. Sizing The Paper

Sizing The Paper. Pour the solution into a clean porcelain or flat rubber dish, and float the paper in exactly the same manner as described for floating albumen paper on the sensitized bath. Before sizing, however, hold the paper to the light so that you can read the water mark correctly. The side showing the water mark is the one which should be salted and sensitized. Lay the paper face down on a piece of clean, dry blotting paper, and on the back of the paper draw a pencil line from corner to corner, being careful, however, not to press down too hard, as this will be liable to injure the face of the paper. This pencil mark will enable you to recognize the unsalted side of the paper after it has been dried. If you do not intend to float the full size sheet of paper, cut to the size desired and then proceed with the salting.

61. The paper may be floated on the surface of the salting bath, or it may be fastened by means of pins on a clean, flat board and the solution carefully brushed over the paper with a camel's-hair brush or a swab of cotton flannel. When employing the latter method the greatest of care must be exercised that the solution be distributed very evenly, for if not done evenly the resulting print will invariably show irregular streaks. If the paper is to be floated on the salting bath, it should be perfectly flat and well dampened before attempting to float it, for if this precaution is not taken the paper will curl and give considerable trouble. The paper should remain in contact with the solution for two to three minutes. After the paper has been sized and salted it will keep almost indefinitely. You may, therefore, prepare a sufficient quantity to last for some time. The salting and sizing solution itself will not keep and should be discarded after having been once used. If the paper has a tendency to curl up at the edges, breathing on it will cause it to lay flat.

Study No 2  See Page 355 A MASHED FINGER. H. B. CONYERS

Study No 2 -See Page 355 A MASHED FINGER. H. B. CONYERS.

02. Sensitizing

Sensitizing. When you are ready to sensitize the paper, prepare the following sensitizing bath:

Distilled or Pure Water.....................

10

ozs.

Citric Acid................................

240

grs.

Silver Nitrate.............................

600

grs.

63. The printing quality of the paper or the solidity of the image is governed by the quantity of silver nitrate present-in other words, the number of grains of silver nitrate in one ounce of bath. If the silver bath is too strong, it coagulates the organic matter, or if too weak, it dissolves it. A weak solution of silver nitrate leaves less free silver on the surface of the paper, and therefore, will not give as rich or as strong an image as a properly proportioned bath. The solution should never test under 40 grains of silver to the ounce. The object of employing citric acid is to prolong the keeping quality of the paper. If not used the paper would darken spontaneously without exposure to the light.

64. Pour the solution into a clean, flat dish the size of the paper you wish to sensitize, and proceed in the same manner as directed for the sensitizing of albumen paper. After drying the paper, if you desire to keep it for a few days in a sensitized condition, fume it the same as you would the albumen paper and place it in a drawer away from the light.