Of hail. may, perhaps, appear paradoxical that vapors should freeze in the atmosphere precisely in the warmest season of the year: but it should be considered that, even during the most intense heat, the upper regions of the atmosphere are extremely cold; otherwise, how could the highest mountains remain covered with snow during the whole summer? Even in the sultry regions of America it is so cold on the summits of the loftiest mountains, that you are in continual danger of being frozen to death. The cold in the upper regions of the atmosphere being so intense, we should have snow in summer, were it not melted before it reaches the earth. These particles of snow uniting, begin to congeal, and as, during their descent, they suddenly pass through warmer regions of air, their cold increases to such a degree before this change of temperature has time to operate, that they are completely frozen. The reader may perhaps conceive that the cold of these descending drops ought to be diminished in proportion as they approach nearer to our warmer atmosphere; but in winter, when you the pouch to permit the insects to escape, when, unable to pass the barrier, they are confined to the tree, and are compelled by hunger to attack and devour the caterpillars which are upon it. Ants, and especially the larger species, residing principally in the woods, exhale a powerful acid, denominated by modern chemists formic acid, and which is a compound of the malic and acetic. The utility of these little insects in the general economy of Nature may perhaps be much more extensive than would at first sight appear. Is it not possible that the acid effluvia continually exhaling from them during the heats of summer, may be one of the means employed by the Creator for preserving the salubrity of the atmosphere? T. Of hail. remove cold water which has stood in the open air into a warm room, what is the consequence? It congeals, and becomes ice, which would not have been the case, if it had been taken into a cold room. Precisely the same effect may be observed with regard to falling hail-stones. When these cold bodies suddenly pass through a warmer atmosphere, but with such rapidity that the warmth has not time to penetrate them, their cold is increased to such a degree that they are converted into ice. To this end contribute also the subtle and volatile saline particles with which the atmosphere more or less abounds. We need not, therefore, be surprized that thunder-storms are not always accompanied with hail; for, in order to produce hail, a certain quantity of saline vapors is necessary to cause the drops of water to freeze more instantaneously. Though hail is most frequent in summer, it falls also in the other seasons; for, as certain fermentations of the saline vapors may at any time take place in the atmosphere, hail may fall in winter, spring, or autumn. The form and size of hail are not always alike. It is sometimes round, sometimes oblong and sharp pointed, and at others flat and concave. Its usual size is that of small shot; the stones are seldom so large as nuts, though they are said to have sometimes fallen of the dimensions of a goose's egg. The precise form and size of hail may depend on many accidental causes. Among these, the principal are the winds, especially when they blow with violence from contrary quarters at the same time. It is likewise possible that in their fall the hail-stones may be continually receiving accessions of aqueous vapors, or Of hail. that several freezing drops may unite and be congealed together. Hail, it is true, when of a large size, does inconceivable mischief to houses, animals, and the produce of the earth: but this by no means authorizes us to regard it as a judgment or punishment of God. If its violence sometimes lays waste a few fields, and breaks some hundreds of windows, this damage, great as we may think it, is a mere trifle in comparison of the obvious advantages which it produces.* Hail moderates the heat in summer, by the cold which it diffuses through the lower regions of the atmosphere; and, dissolving, *We have great reason to congratulate ourselves on our almost total exemption from the calamities which hail occasions in other regions of the globe. In France its ravages are particularly felt. There the husbandman frequently has the mortification to behold the labors of one half of the year, and the hopes of the other, frustrated and blasted in the space of very few minutes. We read of hail in that country, the stones of which have each weighed one, two, nay, even so much as eight pounds. The destructive of fect of such storms on the vegetable and animal kingdows may be easily conceived. The ingenuity of man has, however, discovered a method of dissipating, on their approach, the clouds from which they proceed, and thus preventing the ravages occasioned by them. This is effected by means of cannon, which are placed on eminences, and discharged before the stormy clouds have had time to accumulate in great number; and the explosions are repeated, till they are totally dispersed. This method is said to be invariably attended with the happiest results. It was first practised about thirty-five years ago by the Marquis de Chevriers, at his estate at Vaurenard, in the department of Saône and Loire, and it is now employed, with uniform success, by the inhabitants of the adjacent country to a considerable extent. T. Utility of thunder-storms. it contributes to the fertility of the earth. It is exceedingly remarkable that though all meteors seem to succeed each other without any regularity, and are different in one year from what they were in the preceding, yet this apparent confusion is productive of incessant fecundity. In this also, O adorable Creator, dost thou manifest thy wisdom and goodness; even in the midst of hail-storms will I praise thee, for thy hand doth great things, and giveth us bread in abundance! JULY 11. UTILITY OF THUNDER-STORMS. IT is a duty which cannot fail to appear the more essential to every attentive observer of the works of God, the more it is neglected by the thoughtless, the ignorant, and the ungrateful, to consider all the phenomena of Nature in that point of view, in which the goodness and wisdom of our heavenly Father are rendered conspicuous to the understanding, and are deeply impressed upon our hearts. It cannot, indeed, be denied that God sometimes makes use of natural phenomena to punish the sins of men; but these individual instances nevertheless tend to the general benefit of the whole, which is the primary object of the Almighty. All Nature furnishes incontestible demonstrations of this truth. We shall now confine our attention to one of these phenomena, which is particularly calculated to instruct, and on which subject we want instruction, perhaps more than on any other. The greater part of mankind are accustomed from infancy to pronounce the words thunder and Utility of thunder-storms. lightning with fear and trembling. Such is our ab◄ surdity that we think only of the very small number of instances in which storms are injurious to an extremely small portion of the whole; while we shut our eyes to the numerous and extensive benefits which in every case are conferred by them on mankind, and the universe in general. How different would be our language, if God, indignant at our murmurs and our ingratitude, were to withdraw from us the advantages resulting from thunder-storms. We are not able, it is true, to enumerate all the benefits we derive from these phenomena; but the little we know concerning them is sufficient to fill our hearts with gratitude toward our great benefactor. Figure to yourself, my dear reader, an atmosphere charged with noxious and pestilential exhalations, which are continually receiving accessions from the effluvia of innumerable putrid and poisonous substances on the earth. This air we are under the necessity of breathing; upon it depends the preservation or extinction of life, according to the salubrity or insalubrity of its constituent principles. When oppressed by the sultry heat of summer, have you not felt a relaxation of all your energies, a difficulty of respiration, and a dejection of spirits? Ought you not then to consider it an important blessing, and deserving of your warmest gratitude, that a salutary storm arises to purify the air of its noxious principles, to consume the saline and sulphureous particles, and thus prevent their pernicious effects; to cool the atmosphere, and, by restoring its elasticity, to facilitate respiration? If these beneficial effects were not produced by storms, the noxious matter |