Without the air we could not have the bright blue sky which gives to our fine season its greatest charm. The heavens would be a vault of intense black, in which the sun would appear alone a glaring ball of fire, whose rays, unmitigated by the air which now absorbs them in their passage through its mass, would be a continual source of ill. The blue sky, the bright white clouds, arise from the sun's rays being partly stopped, and turned from one object to another. The sun's rays really consist of light of all the colours of the rainbow; of these the red portion is lost in passing through the air, and the blue remains, giving the colour we observe. Without the air, a place shaded from the sun would be in absolute darkness; as it now exists, a quantity of light is scattered about in every way by the different portions of the air, and thus an agreeable shade provided in place of the total absence of all light. On very elevated tops of mountains, where the traveller is placed above the greater portion of the air, all these effects of its absence which we have noticed, are found to exist. On the summit of Mont Blanc, a pistol discharged is scarcely heard, and a companion once out of sight, may be lost; for neither can he produce any noise by his own exertions, nor could his voice reach his friends, even if he could speak; the sky is deep indigo-coloured, or nearly black; and those objects on which the sun's light does not directly fall, are seen with difficulty. Such are the uses of the common air we breathe. Such are the benefits we derive from a blessing, of whose existence when at rest we are almost unconscious. ABSENCE OF MIND.--A well-known gentleman of Magdalen College, Cambridge, had taken his watch from his pocket, to mark the time he intended to boil an egg for his breakfast, when a friend entering the room, found him absorbed in some abstruse calculation, with the egg in his hand, upon which he was intently looking, and the watch supplying its place in the saucepan of boiling water. EARLY RISING.--Six or seven hours' sleep is certainly sufficient, and no one ought to exceed eight. To make sleep refreshing, the following things are requisite:--To take sufficient exercise in the open air; to avoid strong tea or coffee; to eat a light supper; and to lie down with a mind as cheerful and serene as possible. We hardly ever knew an early riser who did not enjoy a good state of health. It consists with observation, that all very old men have been early risers. This is the only circumstance attending longevity, to which we never knew an exception. Printed and Published every Saturday by GUNN and CAMERON, at the Office of the General Advertiser, 6 Church Lane, College Green, Dublin. TRANSCRIBERS' NOTES