  The study of crystallization is undoubtedly an interesting and fascinating one, and photography may be made to play an important part in securing permanent records of these curious formations. If a drop of water containing a salt be allowed to drop upon a glass plate, it will, upon evaporation, deposite crystals of various kinds. In a recent article in La Nature, by Dr. E. Trouessart, a description is given of the "Take a sheet of glass, deposit on it a drop of ink and spread the drop a little, uniformly; let it dry for a few minutes; then examine with a microscope, magnifying from 50 to 200 diameters, and you will be able to see the flowers of ink in process of formation under your eyes; that is to say, regular white crystal particles which detach themselves from the black or violet medium, and arrange themselves so as to form regular figures. "If you are pressed for time, this beautiful result will easily be obtained by passing the sheet of glass over a spirit lamp or a candle to evaporate the moisture. The crystals will then be smaller and more numerous, presenting the appearance of a dark firmament densely sprinkled with bright silvery stars. But if you have patience to wait for evaporation without heat, you will obtain larger crystals of more varied forms, arranging themselves as crosses, flowers, etc. "These crystals may be varied indefinitely by modifying the compositions of evaporation, adding more ink, etc. But it is quite possible that different inks will give different results. The inks I use, like all the other inks in use, have a basis of sulphate of iron and gallic acid. From "The Literary Digest." "By allowing the evaporation to proceed slowly, it is quite easy to watch the formation of the crystals. The geometrical figures are more or less perfect cubes, pyramids, lozenges, crosses, needles, etc., the pyramids being formed by cubes superposed one on the other, as in the pyramids of Egypt. The flowers in our illustration are formed by the union of crystals, each of which represents the petals or sepals of a flower. The Maltese cross—the crucifer or four-leafed flower—is the normal regular form, but multiples of four frequently occur, by the formation of new crystals in the intervals; and also by the accidents of crystallization, we get flowers of three and five petals, resembling Rubiaceae, lilies, orchids, violets, etc." |
|
