“IF you pass your hand quickly before your face, you feel a breath blow on your cheeks. This breath is air. In repose it makes no impression on us; put in motion by the hand, it reveals its presence by a light shock that produces an impression of freshness. But the shock from the air is not always, like this, a simple caress. It can become very brutal. A violent wind, which sometimes uproots trees and overthrows buildings, is still air in motion, air that flows from one country to another like a stream of water. Air is invisible, because it is transparent and almost colorless. But if it forms a very thick layer through which one can look, its feeble coloring becomes perceptible. Seen in small quantities, water appears equally colorless; seen in a deep layer, as in the sea, in a lake, or in a river, it is blue or green. It is the same with air: in thin strata it seems deprived of color; in a layer several leagues in thickness, it is blue. A distant landscape appears to us bluish, because the thick bed of intervening air imparts to it its own color. “Now air forms all around the earth an envelope fifteen leagues thick. It is the aërial sea or atmosphere, in which the clouds swim. Its soft blue tint causes the sky’s color. It is in fact the atmosphere that produces the appearance of a celestial vault. “Do you know, my children, what is the use of this aërial sea at the bottom of which we live as fish live in water?” “Not very well,” Jules replied. “Without this ocean of air life would be impossible, plant life as well as animal. Listen. Chief of those imperious needs to which we are subjected are those of eating, drinking, and sleeping. As long as hunger is only its diminutive, appetite, that savory seasoning of the grossest viands; as long as thirst is only that nascent dryness of the mouth that gives so great a charm to a glass of cold water; as long as sleepiness is nothing more than that gentle lassitude that makes us desire the night’s rest, so long is it the attraction of pleasure rather than the rude prick of pain that urges the satisfaction of these primordial needs. But if their satisfaction is too long delayed, they impose themselves as inexorable masters and command by torture. Who can think without terror of the agonies of hunger and thirst! Hunger! Ah! you do not know what it is, my children, and God preserve you from ever knowing it! Hunger! If you could have any idea of its tortures, your heart would be oppressed at the thought of the unhappy ones who experience it. Ah! my dear children, always help those that are hungry; help them, and give, give; you will never do a nobler deed in this world. Giving to the poor is lending to the Lord.” Claire had put her hand before her eyes to hide a tear of emotion. She had observed a flash on her uncle’s face that spoke from the depth of his heart. After a moment’s pause Uncle Paul continued: