As introductory to a description of the Arctic Glaciers, a few words on the formation of snow seem necessary. Briefly, it may be said that snow is the result of the crystallization of water. The molecules and atoms of all substances, when not constrained by some external power, build themselves up into crystals. This is true of the metals and minerals, if, after having been melted, they are allowed to cool gradually. Bismuth develops the process in a very impressive manner, and when properly fused and solidified exhibits large-sized crystals of singular beauty. In like manner, sugar dissolved in water produces, after evaporation has taken place, crystals of sugar-candy. The ready crystallization of alum is known to every school-boy who has dabbled in “chemical experiments.” Chalk dissolved and crystallized becomes Iceland spar, and assumes a variety of fanciful and graceful shapes. The diamond is crystallized carbon; and the crystallizing power is inherent in all our precious stones,--sapphire, topaz, emerald, beryl, amethyst, ruby. In the process of crystallization, it is found that the minutest particle of matter is possessed of an attractive and a repellent pole, and that by their natural action the form and structure of the crystal are determined. The attracting poles, in the solid condition of any given substance, are firmly interlocked; but dissolve the cohesion by the application of sufficient heat, and the poles will recede so far as to be practically beyond each other’s range. And thus the natural tendency of the molecules to build themselves together is neutralized. Water, for example, as a liquid is, to all appearance, without form; but when sufficiently cooled, its molecules are brought under the influence of the crystallizing force, and then arrange themselves in the most varied and beautiful shapes. When snow falls in calm air, the icy particles present themselves in the form of six-rayed stars. From this type there is no departure, though the appearance of the snow-stars in other respects is infinitely varied. It is worth pausing, as Professor Tyndall remarks, to think what wonderful work is going on in the atmosphere during the formation and descent of every snow-shower: what “building power” is brought into play! and how imperfect seem the productions of human minds and hands when compared with those produced by the forces of Nature!