the law of oscillation. A pendulum in motion seeks to rest in a position in the straight line which joins the centre of the earth with its point of suspension, but, in coming to this place, it comes with too much force, and first of all passes over it to the opposite side.

Objects, whose temperature is different, placed at any distance from each other-though only seen by us when they are near-seek a state of repose. The heat of the hotter flies off in the direction of the colder, to bring it up to a common standard. The colder object is warmed and the hotter is cooled, until at length both have equal temperature; or, to speak more in harmony with modern science, the molecules which move faster and at a greater distance from each other, communicate their motion to those in the other objects, which are more sluggish, until the ultimate particles of both have attained a common velocity. The hotter object in becoming cool goes at first beyond the point of equality, and becomes the colder of the two. The other then begins to heat its neighbour, and both, after many oscillations, arrive at a state of repose, or of equal temperature.

Some substances part with their heat by radiation, much more quickly than others. Grass radiates heat, and thus cools much more quickly than earth or stone, or wood or metal.

When the sun has ceased to heat the grass or ground, or space being colder than the atmosphere, the latter begins to radiate or send forth its heat to the colder region. The air becoming colder than the ground, the latter pours forth its heat to restore the equilibrium of temperature. But owing to the law of oscillation, the ground becomes ultimately colder than the atmospheric stratum nearest to its surface, and owing to the motion of the air a little further from the ground, the strata above become warmer than those below. The stratum in which the grass grows, and in which the trees wave their foliage, becomes too cold to hold the vapour molecules at a distance from each other. Their speed is slackened, and many of them coalesce so as to become too heavy to float in a mere mechanical mixture of gases, such as the atmosphere is. They gently sink and rest upon the grass below, and, uniting in larger groups, they form the glittering drops which dance in the moonlight on the quivering leaf, and sleep in the warm bosom of the flower.

If, however, the air moves much, and moves near the ground, as motion is heat in another form, the requisite cold temperature is not attained, for the condensation of invisible vapour, and no dew falls.

If a screen of wood, or glass, or thinnest gauze be placed above the grass, the heat, radiated by the earth and its covering of vegetation, strikes the screen, and, though some be absorbed, a large portion is reflected back again, and the temperature never becomes low, and the dew is not deposited under these conditions. The clouds are

screens above the ground, which reflect back to the earth again the heat it lost by radiation. No dew is formed, therefore, on a cloudy night. The clearer the sky, other things being equal, the more copious the fall of dew.

Hoarfrost is dew solidified or frozen, and is formed of an indefinite number of crystals, whose beauty must be seen to be conceived.

One more fact must not be forgotten. If a piece of ice be taken, whose temperature is 32 deg. Fahr., and heat applied to it, much heat will be consumed to melt the ice and make it water, and yet, notwithstanding the consumption of all that heat, the temperature of the water is but 32 deg. Again, when water boils, its temperature is 212 deg. Fahr., and an immense amount of heat is used in the conversion of water into steam or vapour, and yet the temperature of steam at the first is only equal to that of boiling water-212 deg. The hest absorbed in either case becomes imperceptible or latent. The law is this-When a solid becomes liquid, it absorbs heat, and when a liquid assumes the form of vapour heat disappears. Evaporation is therefore cooling. The heat of a burning sun is counteracted in its injurious consequences by cold produced by the absorption of heat in the process of evaporation.

The result of condensation is the reverse of this. The heat absorbed on a hot day by the change of water into invisible vapour is given back again, without change or diminution, when that vapour becomes the pearly dew; and the heat absorbed by the ice in becoming water is set at liberty to warm the world on the cold night when the dew becomes hoar frost.

B.-Special points of interest in these facts.

Dew (a) is the purest water in nature, being free from mineral impurities. Rain water, owing to the disturbed action of the atmosphere, when it falls, contains carbonate of ammonia, and during a thunderstorm nitrate of ammonia and other impurities. Dew (b) is the result of a combination of the smallest aqueous molecules; (c) falls plentifully when there is no rain, there being no clouds; (d) falls only when the air is chill; (e) never falls copiously on hard or metallic substances, because these are bad radiators of heat; (f) falls only when the air is still; (g) when the sky is clear, (h) chiefly in the night; (1) falls most plentifully on those objects which are nearest the surface of the earth. Dew in the act of forming () gives out heat, and thus warms the night air, and keeps alive the growing vegetation. Dew in freezing, or in becoming hoar frost, gives forth the greatest heat, and that when the night is coldest and the vegetation needs its protecting influence the most: this is hoar frost.

C-Application of these facts to some of the texts of Scripture. Conscious of the difficulty of revealing heavenly and spiritual

truths so as to be comprehended by men whose habits of life and associations were earthly and carnal, the sacred writers made use of a large number of figures. Among these, the dew stands pre-eminent as to the variety and beauty of its meanings. The fact of the dew-fall is referred to in Num. xi. 9. Its divine origin is spoken of (1) naturally in Job xxxviii. 28, where the patriarch asks, "Who hath begotten the drops of dew?" and (2) miraculously in Judges vi. 37-40, where Gideon seeks to know the presence of God first by finding dew upon the fleece while none was on the ground. This might have been the case without any supernatural interposition, as the fleece was a better radiator of heat than the earth, and therefore would of necessity be covered first with moisture. The second test required absolutely some superhuman interposition, for, according to it, the fleece was to be dry while the ground was to be covered with dew. The manner in which the dew is formed is also spoken of-gently, softly, and imperceptibly, its first indication being its actual presence. This is mentioned to illustrate (a) the stealthy approach of an army (2 Sam. xvii. 12); and (5) the kind and gracious words of God (Deut. xxxii. 2). The evaporation of the dew, which happens when the heat of the rising sun has become sufficiently great to change the dewdrops into vapour, forming the mist of morning, which disappears when the temperature of the air is raised a little further, the evaporation of dew is spoken of (4) as a fact in Exod. xvi. 14, "When the dew had gone up;" and (6) as illustrative of transitory goodness, in Hosea vi. 4, "For your goodness. . . . as the early dew goeth away." In the majority of cases, however, the sacred writers refer to the refreshing influence of dew. It is impossible to exaggerate the value of dew in Western Asia, as but little rain falls from April to September, the existence of both animals and plants being dependent upon the refreshing influence of dew during the hot months of summer. Hence we find that to have dew, in the case of Jacob (Gen. xxvii. 28), is to have temporal prosperity, and to be far from the dew, as in the case of Esau (b. xxvii. 39*), is to suffer temporal privations; and the loss suffered by the country by the death of Saul and Jonathan is spoken of as the cessation of dewfall upon the mountains of Gilboa (2 Sam. i. 21). As

*Our authorised version of this verse is very inaccurate, though it follows all the ancient versions and most of the modern ones, "Behold, thy dwelling shall be the fatness of the earth, and of the dew of heaven from above; and by thy sword shalt thou live, and shalt serve thy brother," which Nachmanides explains thus: "The fatness of the land and the dews of heaven I can wish for thee also, but the dominion over thee must abide with thy brother." (See Dr. Raphael, in loco.) It is better, however, to understand the m in mishmanney, fatness, and in mittal, dew, as min in the sense of a negation. It is so understood by Vater, Von Bohlen, Tuch, Knobel, and the best critics. The min has often this negative meaning in the sacred book, as in Job xi. 15, mittum, "without spot; " and ib. xxi. 9, "safe from fear," mippachad. In this case the text would thus read: "Behold, away from the fatness of the land shall be thy dwelling, and away from the dew of heaven from above." The home of Esan was the barren hills of Edom, while that of Jacob was the fertile felds of Canaan.

VOL. XX.

I

the dew of night restored the elastic texture, the upright form, of plants, and the blushing tints of flowers, whose life had all but been destroyed by the scorching sun, and made them young again, so full vigour of frame, and youthfulness of health, were spoken of as dew'te dew of youth" (Psa. cx. 3; Isaiah xxvi. 19). The dew also, most graphically, represents the elevating and saving influence of pious men upon ungodly people-"And the remnant of Jacob shall be in the midst of many people as a dew from the Lord" (Micah v. 7). The realisation of the Divine presence by faith, spoken of by Hosea (chap. xiv. 5), embraces all the analogies of the dew: for-1. As the dew is the purest water in nature, so is the realised presence of God the truest bliss; 2. As the dew falls most copiously when it is night, and when the night is cold, so is the presence of God most fully realised when life is dark and cold with trouble; 3. As the dew falls only when the sky is clear, so is God's sacred presence felt only when the world is beneath our feet, and when no object intervenes between our soul and the clear heaven; 4. As the dew falls only when the air is still and all is quiet, so do we feel God's presence when, out of bustle, we are alone; 5. As most dew falls upon those objects which are near the surface of the earth, other things being equal, so is God's presence most fully felt by the humble soul; and, 6. As the dew was essential to the growth and beauty of vegetation, so is a realisation of God's presence by faith essential to the life and beauty of the human

soul.

The references to hoar frost are insignificant, though appropriate. Exod. xvi. 14; Psa. cxlvii. 16.

Preston.

EVAN LEWIS, B.A., F.R.G.S., F.E.S.

Seeds of Sermons on the Book of

(No. LXXVI.)

Proverbs.

THE QUEEN OF THE HOUSEHOLD. "A virtuous woman is a crown to her husband."-Prov. xii. 4.

FEW men understood more of woman than Solomon. He knew her frailties and her virtues, and his writings abound with many sage remarks upon the subject. Here he speaks of a virtuous woman, and a virtuous woman is

a true woman, chaste, prudent,
modest, loving, faithful, patient
in suffering, and brave in duty,
keeping within the orbit of her
sex, and lighting it with all the
Such a
graces of womanhood.
woman, Solomon says, is a crown
to her husband. This language
implies two things.

I. THAT SHE EXERCISES A CONTROL OVER HIM. A "crown" is the insignia of rule. A virtuous