GIRLS TAKING EACH OTHER'S PHOTOGRAPHS.
Among other things we bought with the camera were three shallow pans and four paper boxes containing dry chemicals, together with a few cents' worth of oxalic acid in dry powder, a little sulphuric acid in a bottle, and a bottle of dry bromide of ammonia. We shall also find a small pair of scales and weights useful.
Now for work. Open the box marked neutral oxalate of potash, and weigh out two ounces, and put it in a bottle with six ounces of hot water. Then to this add a few grains of the oxalic acid. For measuring the water we use a glass graduate. From the box marked protosulphate of iron weigh out two ounces, and put it in a bottle with six ounces of hot water. To this add six drops of sulphuric acid. Let them stand until they are cool. From the box marked hyposulphite of soda take one ounce, and from the box marked alum two ounces, and put the chemicals in bottles containing six ounces of cold water each. Lastly, weigh out one hundred and twenty grains of the bromide of ammonia, and mix with two ounces of cold water. Pour the first two mixtures into clean bottles, taking care to keep back the sediment. For convenience, we will call the bottle of oxalate of potash No. 1, the iron mixture No. 2, the hyposulphite of soda No. 3, and the alum No. 4.
After supper we will light the lantern, open our picture game-bag, and see what we have captured. On the table we place the three pans, the numbered bottles, and bromide of ammonia, which is called the "restrainer." Now measure out one ounce of No. 1, and put it in one pan. Then add one-quarter ounce of No. 2, and a few drops of the "restrainer." In another pan pour enough of No. 3 to cover the bottom, and in the third some of No. 4.
Open one of the boxes, and take out a plate. Hold it right side up for a moment in a bowl of cold water, and then drop it lightly into the pan containing Nos. 1 and 2. Hold the pan in front of the lamp, and gently rock it up and down. Why, look at that! See that black spot on the plate. There's another in the corner. Oh, that's the sky. There are two more spots. That is—yes, that's the girl's dress. There's her face, and those two small spots are her hands.
Now wash the plate at the sink, and place it in the pan containing No. 4 for a moment. Then take it out, and put it in the pan containing No. 3. How strange! The picture is fading away. No. That's all right. Wait a moment, and then hold it up to the light. There it is, with the white film quite faded away. Give it one more washing, and place it in No. 4 for five minutes. Take the other plates and treat them each in the same way.
Next day we find that our four plates are regular photographic negatives, and if we take them to the photographer, he will give us prints of them at a very low price. Keep the negative, for if it is a very pretty one, you can have as many prints made as you wish. Another and cheaper way is to print them yourself. We buy a little picture-frame having a movable back, and called a printing-frame. We place in this one of the negatives, with the smooth side out, and lay over it a piece of paper called ferroprussiate paper, or sensitive paper, and locking the back of the frame, we put it in the bright sunshine for three or four minutes. Then we open the frame in a shaded room, and taking out the paper, we put it in a pail of water in a dark closet, and leave it floating there for half an hour. When we open the closet, we take out the paper, and hang it up to dry in the dark. When it is dry, there is the picture, in blue and white.
Any boy or girl twelve years old can do this work. The new tools cost only a few dollars, and they bring a great deal of fun, and in a little while a whole gallery of pictures.
P.S.—Don't forget to send the picture to the girl as we promised.