Many beautiful crystals may be obtained by dissolving various substances in gelatine or gum. The method is simple. Gently warm a little gelatine, to which is added an equal volume of water, in a chemist’s test-tube. When the gelatine has all dissolved make a saturated solution of the substance, from which crystals are derived. Green or blue vitriol are good subjects for the experiment. Add a little of the saturated solution to the gelatine and stir with a glass rod, taking care to avoid the formation of air bubbles. A little of the mixture may now be placed in a thin film on a slide covered with a cover slip and left to cool. Examination when cool under the microscope will show lovely fern-like crystals, whose beauty rivals that of ice crystals familiar to us on our window panes during hard weather in the winter. Barium chloride also produces very beautiful fern-like crystals when treated in this manner. Chlorate of potash, familiar to most of us as a remedy for sore throat, forms crystals totally dissimilar to those substances we have named. Having made as many crystals as we wish from water and also from gelatine solutions, we may turn our attention to gum arabic. The method of obtaining crystals from this substance is exactly similar to that described for gelatine except, of course, that we substitute gum for gelatine. This work is of the greatest interest, for not only does it yield wonderfully beautiful objects for our microscope, but it is a hobby full of surprises. When we are about to examine a new crystal for the first time we can never so much as hazard what shape it will assume. Sugar, it may be mentioned, does not crystallize at once from a saturated solution in water, and the best method of obtaining the crystals is to warm the slide, on which we have placed a drop of solution, and then when dry to set aside for a day; at the end of that time, especially if the air be moist, the crystals will have formed. We shall find it interesting to try experiments in mixing two different substances, then we shall probably obtain crystals totally unlike those of either of the ingredients. As an example of this method, let us make a saturated solution of a mixture of blue vitriol and magnesium sulphate in water. Place a drop of the solution on a slide, heat over a flame, not only till dry, but till the substance left on the slide begins to melt. We must use every care not to crack the slide, and this may best be accomplished by keeping it moving while over the flame. Now if we watch our object through our microscope we can witness the formation of wonderful feathery crystals, as the slide cools.