For those who have regularly fitted up printing-rooms this is not intended, but to those who are still printing by the "cold, open window," it will surely be a boon. Havings platform outside of my window, just as a good many-others have, some three feet by four, I conceived the idea how easy it would be to get a sash made to fit. I got one that just reached from the outer edge of my platform to the lower edge of the upper sash of my window. I then had the ends enclosed, and the whole fitted up; putting in glass just as in my skylight. My window will hold from fifteen to eighteen negatives, and can print in all kinds of weather. Every artist knows that prints are very much improved by keeping thorn warm; then it is so comfortable, and removes much of the unpleasantness of the work in winter time. - J. S. Young.
It is much to be desired that more intelligence be imparted into the printing operations, for it is only reasonable to expect that if it he impossible with one negative nitrate bath of inferior strength, with one kind of collodion more modified, and with a developer of unvarying ambition, to fascinate you, and to repay you for all the pains you exer rise in order to produce the best possible results. Indeed, the negative may be ever so perfect and good, yet the printer may spoil all if he is heedless and indifferent. As the artist who makes the lovely sketch upon the block is so often disappointed by the murderous hatcheting of the engraver, so is the negative-artist sickened by the careless handling of his work by him who should be equally an artist - the printer. There should be a harmonious working - a mutual understanding - between the two; they should operate and think together.
247. The best results are obtained on albumen paper, which is supplied of various excellent brands, ready made, by the dealers. Few underproportions, to produce every variety of effect in the negative, so is it equally impossible, from paper always the same as to the proportion of albumen, salt, and silver, to get perfect proofs from all kinds of negatives as opposite in their characteristics as photography can make them. - Valentine Blanchard.
246. I have used this bath for six or eight months without having it once hardly more than perceptibly discolored, even after a hard day's work. It is made as follows:
1. - Nitrate of Silver,..................
To every eighty ounces of solution add of a
Upon adding the sal soda, the bath will turn creamy in color; let it settle for a while, and then filter the decanted solution. There will be a deposit in the bottle, which will take the organic matter from the bath, and render the solution always clear. This deposit, which is the carbonate of silver, should always remain in the bottle, and the solution poured into it after use; then shake up, and it is ready for use again in a very short time. By the use of this bath the solution will always be clear, and the only thing required in its management is to add solution from a stock to keep it up to some number of ounces - eighty, for instance - and every few days add a few drops of the sal soda solution. It is an excellent bath.
2. - Nitrate of Silver,..................
Nitrate of Ammonium,..................
. 35 "
Filter this solution through filtering - cotton,after having placed a piece of alum about the size of a small filbert in the funnel, and then the solution will take up some of the alum, which it surely needs.
This alum, by the way, is one of the best things that can possibly be used in the bath outside of the silver, as all photographers who have used it can vouch for. Both it and nitrate of ammonium, besides coagulating the albumen on the surface of the paper, also improve the tone of the unfinished print, giving remarkable richness and beauty to the whole print, thus rendering it an easier thing to obtain finer tones, although still considerable skill is required. - Charles "W. Hearn.
247. The negative having been obtained, the next step is to produce positives from it. The fact long known to man, that nitrate of silver in the presence of organic matter darkens take to albumenize their own paper, so no instructions as to that are called for here. The sheets of paper are taken in the hands and floated carefully, albumen surface down, upon a solution of nitrate of silver made as follows:
16 ounces (fluid)
Nitrate of Silver,........................................
Dissolve the silver in the water, and aeparate one - fifth from the rest. To this add liquid ammonia until the brown oxide of silver redissolved, after which it should be added to the remaining four - fifths. Oxide of silver will again be precipitated; this should be redissolved again with chemically pure nitric acid , being careful not to add too much. This will leave the solution slightly alkaline. It is not liable to turn red, unless it is allowed to get exhausted.
in sunlight, is utilized for this purpose. In darkening, it is probably reduced to a sub-nitrate, but why it should be reduced, and why in the presence of organic matter, is a question that will not be proposed here, because its answer would lead so far into the fields of theoretical chemistry that we might find ourselves more in shadow than before we entered those holy domains. The fact is certain, that the nitrate does darken when exposed to the sun, and it is also true that this fact is utilized in obtaining positive prints. The paper is first albumenized, because it gives a fine, smooth finish to it, and allows it at least to work as fast as the plain paper. When this is floated upon a nitrate of silver bath, albumenate of silver is formed; but as there is also free nitrate of silver present, and as it is a no much simpler salt, and as the reactions are similar, we will consider it as nitrate of silver in the presence of organic matter - albumen. A piece of paper is then taken, with a coating of albumen, and coated with nitrate of silver and allowed to dry. If now this is used to print with, it would be found that the reaction would be retarded by the nitric acid that would be set free (nitric acid being liberated in this case in the same way that we have seen chlorine, bromine, and iodine liberated before). Something is evidently needed to seize upon the escaping nitric acid, and by uniting with it prevent it from doing any damage. This "consummation devoutly to be wished" is obtained by the "fuming," when the sensitized papers are hung up in a box and subjected to the fumes of ammonia. Those fumes, acting up the nitrate of silver on the paper, form with it ammonia-nitrate of silver. So then when the paper is placed under the negative, and the light acts upon it, and in acting upon it disengages nitric acid, this nitric acid instead of escaping, instead of retarding the action of the light, seizes upon the ammonia, forms nitrate of ammonia, and then as a retarding agent its work is at an end. The sensitized paper having been exposed for a sufficient time is, as every one knows, taken from the printing-frame and washed in water; washed so as to remove the free nitrate of silver; after being washed in several changes of water it is transferred to the toning - bath. - H.M.Mcintire.