Thence, in the coming days of the hot summer, it will issue bright and sparkling to feed the springs and rivulets that glisten over the land and delight us with their freshness.

Dew may be considered as a kind of supplemental rain, depending on the same cause, namely, a condensation of moisture from the atmosphere. There is, however, this difference between them, that, while rain is formed at a greater or less height in the air, dew is formed on the surface of the ground.

We need scarcely remind the reader that air-even the dryest-always contains invisible vapour. During the day, the earth and the air correspond sufficiently in temperature to prevent precipitation. But as the sun begins to set, the earth, losing its heat by radiation, suddenly cools, and condenses out of the air in contact with it a portion of its invisible vapour. Whatever favours the rapid cooling of the earth's surface promotes the formation of dew. In cloudy weather heat is radiated as usual from the earth after sunset, but it is intercepted by the clouds, and radiated back towards. the earth. The temperature of the latter, therefore, does not fall so much, and little dew is formed. But in clear weather the earth rapidly radiates its heat into space, and there are no clouds interposed to radiate it back. Hence the earth cools quickly and much dew falls. When gardeners cover up their plants on bright evenings they act in accordance with scientific principles. The matting prevents radiation from the soil; or, rather, the matting takes the place of clouds, and gives back to the earth much of the heat it receives. In this manner the atmosphere round the plants retains an equable temperature.

Dew is twice specially introduced into the Benedicite, from which we may infer the importance attached to it

in the countries with which the Three Children were familiar. In most parts of western Asia little rain falls from April to September, and during this long period of drought the earth is dependent upon dew for the scanty supply of moisture it receives. And how clearly indicative of providential design it is that dew should be most abundant precisely at that season of the year when the supply of moisture from other sources is most apt to fail. Scripture abounds in allusions to dew which, like rain, is always associated with what is good and beneficent. The "dews of Hermon" blessed the land where they fell, and the prosperity they brought passed into a proverb. When a patriarch wished to bestow his blessing, he prayed that "God might give of the dews of heaven;" on the other hand, there could be no more withering curse than what was implied in their withdrawal. "Ye mountains of Gilboa, let there be no dew, neither let there be rain upon you.”

From what has been said it will be perceived that, though we commonly speak of dew "drops," dew does not really "drop" from the sky, but forms upon the surfaces where it is found. Yet which of us would consent to surrender an expression that has been endeared to us by familiar associations since childhood? Dew "drops" create for us the most perfect diamondgardens in the world. Well may they challenge comparison with their costly rivals. What diamonds could be brighter, or more sparkling, or play more fancifully with the rainbow colours of light? How incomparably finer, too, the setting! The rare jewel is mostly to be seen in the worn atmosphere of crowded rooms, and, like an artificial beauty, requires the skilful hand for its display. Its brightness pales before the light of day, and needs the garish lamp to stimulate its sparkling. But the diamonds of the garden or the meadow are

perfect from nature's hand. They are set with boundless profusion on a ground of choicest green, and no art can heighten their new-born loveliness. They are to be seen best in the fresh air of the morn, and the light that suits them best is the pure light of heaven.

Thou, O God, sentest a gracious rain upon thine inheritance, and refreshedst it when it was weary.

Ps. lxviii.

WELLS.

O ye Wells, bless ye the Lord: praise Him, and magnify Him for ever.

N a song of praise offered by the children of the East to the Giver of blessings, it was to be expected that the "springing wells" of the earth would not be forgotten. In many districts of southwestern Asia showers are scarcely seen from April to September. The "latter rains" which fell in spring have run off, or been absorbed, or evaporated; and the land, thirsty and parched, receives only its precarious supply of dew. The smaller streams and rivulets have dwindled into dryness also, and the people must then depend on their wells for all the purposes of the household. He whose lot is cast amid the civilization of the West can scarcely realise the feeling of thankfulness with which wells are regarded by the Oriental. In the wide desert they indicate the halting points by which travellers direct their route. Districts are named from their wells. Their seemingly fortuitous appearance amid the sands is often a mystery, but nothing can be more obvious than that they are providentially placed there for the purpose of making those wastes passable. The overflow of the well,

as it sinks into the sand around, illustrates in a remarkable manner the fertilising power of water, and the debris of successive vegetations at length creates an oasis of the richest soil-an island of verdant beauty in the midst of a sea of sand. The surface is softly carpeted with grass, while date-trees and other kinds of palms beckon the traveller towards it from afar, and shelter him from the sun. What can be more natural than that the pious Arab should approach those wells with thankful emotions, or that while quenching his thirst he should seldom omit a prayer both for him who originally dug the well, and for the owner who generously permits it to be used? To poison a well is an act which in the East is considered to be justified only by the extremity of warfare, while its complete destruction is thought to be little less than sacrilege. The well is universally held to be a special gift of God intended for all his thirsty creatures.

The wells that form in the coral islands of the Pacific seem even more strikingly providential than those of the desert. Scarcely has the bare rock risen above the waves before it begins to possess its well of water. The salt ocean is without, and the salt ocean fills the lagoon usually included within, yet, on the mere rim of coral rock that lies between, fresh water is to be obtained when a hole is bored. So generally is this understood by sailors that they are in the habit of touching at those solitary spots to fill their tanks. Thus, in the formation of what is soon to be another island added to the fertile area of the world, wells of fresh water are the first provision made for its future inhabitants. Whence comes this water? The common opinion is, that it freshens itself in filtering through from the ocean; but Darwin, after much attention to the subject, considers it to be the mere surface drainage of the island.

Holy Scripture abounds in allusions to wells, and