The first warm Snows of August and September (says Dr. Kane), falling on a thickly-bleached carpet of grasses, heaths, and willows, enshrine the flowery growths which nestle round them in a non-conducting air chamber; and as each successive snow increases the thickness of the cover, we have, before the intense cold of winter sets in, a light cellular bed covered by drift, seven, eight, or ten feet deep, in which the plant retains its vitality. Dr. Kane has proved by experiments that the conducting power of the snow is proportioned to its compression by winds, rains, drifts, and congelation. The drifts that accumulate during nine months of the year are dispersed in well-defined layers of different density. We have first the warm cellular snows of fall, which surround the plant; next the finely-impacted snow-dust of winter; and above these the later humid deposits of spring. In the earlier summer, in the inclined slopes that face the sun, as the upper snow is melted and sinks upon the more compact layer below it is to a great extent arrested, and runs off like rain from a slope of clay. The plant reposes thus in its cellular bed, safe from the rush of waters, and protected from the nightly frosts by the icy roof above it. IMPURITY OF SNOW. It is believed that in ascending mountains difficult breathing is sooner felt upon snow than upon rock; and M. Boussingault, in his account of the ascent of Chimborazo, attributes this to the sensible deficiency of oxygen contained in the pores of the snow, which is exhaled when it melts. The fact that the air absorbed by snow is impure, was ascertained by De Saussure, and has been confirmed by Boussingault’s experiments.--_Quarterly Review_, No. 202. SNOW PHENOMENON. Professor Dove of Berlin relates, in illustration of the formation of clouds of Snow over plains situated at a distance from the cooling summits of mountains, that on one occasion a large company had gathered in a ballroom in Sweden. It was one of those icy starlight nights which in that country are so aptly called “iron nights.” The weather was clear and cold, and the ballroom was clear and warm; and the heat was so great, that several ladies fainted. An officer present tried to open a window; but it was frozen fast to the sill. As a last resort, he broke a pane of glass; the cold air rushed in, and it _snowed in the room_. A minute before all was clear; but the warm air of the room had sustained an amount of moisture in a transparent condition which it was not able to maintain when mixed with the colder air from without. The vapour was first condensed, and then frozen. ABSENCE OF SNOW IN SIBERIA. There is in Siberia, M. Ermann informs us, an _entire district_ in which during the winter the sky is constantly clear, and where a single particle of snow never falls.--_Arago._ ACCURACY OF THE CHINESE AS OBSERVERS.