Oh, don't let that color trouble you; it will be all black by to-morrow.
“Much obliged to you for this bit of consolation!”
Besides, it will take you a week to grow a new skin. In future you must soak your fingers in pure water whenever you have got them into the acid. You might have used india-rubber finger-gloves; they are excellent to keep the hands clean, but it is not worth while to trouble about them for the present, as we are almost done.[10] I think you may now stop out all that remains, with the exception of the darkest places in the foreground, to which we must give a final biting.
There! Now we've got it! Withdraw your plate for the last time, and as there are some very widely spaced lines in this tree in the foreground, you will risk nothing by giving them a final touch with pure acid. The strongest accent in the landscape rests on this spot; it determines the color of the whole. By this application of pure acid we shall get a vigorous tone, a powerful effect.
I may as well tell you here that it is sometimes advisable to add a small quantity of pure acid to the bath towards the end of the operation, so as to increase the activity of the biting on certain parts of the plate without running into excess. But as the place now under consideration is restricted, we shall adopt another means, so as to limit the action of the acid to the given point. See here: I let fall a few drops; the pure acid eats into the copper with great vehemence; the metal turns green, and the ebullition subsides. Now take up the exhausted liquid with a piece of blotting-paper, and let us commence again. Under these newly added drops of fresh acid, the varnish is ready to scale off, the lines sputter, and assume a strange yellow color; these golden vapors announce that the operation is finished.
What follows, is the task of the printer; his press will tell us whether we have won, or whether we have been mated. Clean the plate with spirits of turpentine, using your fingers, or with a very clean old rag (calico, if possible), if you are afraid to soil your hands. Be sure to have the plate well cleaned, but take care not to scratch it.
The acid, which may be of use hereafter, we will turn into a glass bottle with a ground stopper, and will store it in some safe place.