the air and the soil. All the available water of plants, leaving out the sea-weeds, comes from the air in the form of rain, and was previously diffused through it as vapor. Plants stand between us and the organic world. They separate from air and soil these necessary ingredients, and then give them to us as food. Schleiden treats this subject with his usual elegance:

"In the Pampas of South America," he says, "existed at the period of their occupation by the Spaniards, the same thirsty vegetation of the steppes as at present, excepting that the immediate vicinity of the towns has been altered by the running wild of the great Pampas thistle and the artichoke, the same scanty population, the same quantity of indigenous animals, that now wander over its desert plains. The Spaniards introduced the horse and neat cattle; these multiplied in an incredibly short time in such profusion, that Monte Video alone annually exports 300,000 ox-hides; that the military expeditions of General Rosas cost many hundred thousand horses, without any diminution being observable.

"The native organic life and its quantity have, therefore, since the discovery by the Spaniards, not diminished, but importantly increased, and millions of pounds of carbon and nitrogen, combined into organic substances, have been exported in the trade in hides, without the land receiving the smallest appreciable return of organic matter. Whence could these masses have come, if not from the atmosphere? If we leave out of view all the other constituents of tea, China exports more than 300,000 pounds of nitrogen in the half per cent. of them, without receiving any considerable return.

“The hay-maker of Switzerland and Tyrol mows his definite amount of grass every year on the Alps, inaccessible to cattle, and gives back not the smallest quantity of organic substance to the soil. Whence comes this hay, if not from the atmosphere? The plant requires carbon and nitrogen, and in South America, in the woods, and on the wild Alps, there is no possibility of its acquiring these matters, except from the ammonia and carbonic acid of the atmosphere.

"The northern provinces of Holland, Friesland, Groeningen and Dreuthe, export annually about a million pounds of nitrogen in their cheese. They obtain it through the cows from their meadows, which receive no manure but that from the cattle grazing thereon. The meadows receive no return by this, since all that the cows produce comes itself from the meadows. Whence, then, these enormous quantities of nitrogen? Perhaps Vesuvius

or Etna, or the great fire-abysses of the Cordilleras, pour forth this abundance of carbonate of ammonia, which is carried by currents of air to the plants of the Dutch meadows, and then, through the cows, becomes, as casein, an object of trade and of delight to the palate."

It is manifest that this nitrogen must have come from the atmosphere, but the question arises, in what way? It has been rendered probable, by experience, that a portion of this nitrogen may be derived directly from the nitrogen of the atmosphere, but the greater portion of it is generally believed to come from ammonia and nitric acid. These substances are abundantly formed from the atmosphere. The nitrieres artificielles of France supplied saltpetre enough for the gunpowder used in the early years of the wars of the Revolution, and the nitric acid so obtained came exclusively from the atmosphere. Ammonia is the result of all animal decay, and is also capable of being formed directly from the air. Charcoal, heated to redness in a stream of moist air, generates carbonic acid indeed, but we find the acid combined with ammonia. The explanation is simple. The oxygen is abstracted from both the air and the water, but in leaving the latter, it sets at liberty hydrogen, which, being in a nascent state, combines immediately with the nitrogen of the atmosphere. Iron, rusting, produces the same result. A thunder storm, also, by its repeated discharges of electricity through the moist air, causes another set of combinations to take place. Nitric acid and ammonia are both formed, and these unite to form the nitrate of ammonia, which plays an important part in the economy of nature. Falling upon the inert carbonate of lime in the soil, a double decomposition takes place, and two soluble salts, nitrate of lime and carbonate of ammonia, are ready to enter the pores of the plant.

But there is more than all this in the atmosphere. The scientific eye sees, in those blue depths, a great charnel-house into which countless remains of living things have been breathed. They are full of the products of decay in some of which the final process is not yet completed, which are indeed still dying. These substances are in a state of change, and communicate the peculiar motion of their particles to the living beings with which they

come in contact. Recent researches have gone far to show cholera is dependent upon such fermenting miasmata. They are at all times floating in the air. Invisible to us, they are nevertheless there, and pure as is the crystal vase which contains them, it is false to the old superstition, and does not betray the secret poison which has been infused into it. Inevitable as death are these his active ministers. When, from any cause, they are present in undue quantity, then comes the pestilence. No one can refuse them; they are absorbed with every breath we draw, and diffuse the dire venom through our burning veins.

So goes the scourge, wandering silently and invisibly through

the still air, till its own time comes. The hazy atmosphere becomes bright and cool; a new power has sprung to birth. Like an elemental fire, it leaps through the clear air, consuming these deadly atoms which cannot exist in its presence. The pestilence ceases; the newly smitten recover, and the cloud of death rolls away from the redeemed city.

Though long exerting its benign influence, this substance remained till lately unnamed and unknown. Schoenbein discovered it and named it ozone. What it is can hardly be determined. Some chemists regarding it as a union of a large amount of oxygen with a small quantity of hydrogen, while others conceive it to be a modification of oxygen produced by electric force. Whatever may be its composition, it is certainly a most powerful oxydating agent, and renders these substances harmless by hastening their final changes to compounds of highest oxydation.

We have thus taken a rapid, and necessarily imperfect survey of the uses of the atmosphere. There remain, however, many important questions to be discussed, but it would be idle to attempt to compress these into our limited space.

Of the aesthetics of the atmosphere we have as yet said nothing, though that alone would form the subject of a distinct treatise. We are indebted to it for all the visible beauties of nature and art; for all the audible delights we experience.

It is to the air we owe all the vegetation which covers the surface of the earth. Were it not for it, this green earth would be an unsightly heap of ruins; the monument of the Titanic

struggle of the early geological forces. Those primeval throes of the world have indeed left their trace upon the surface of our planet. Great mountains still record that awful time when the earth heaved like a stormy sea, but was checked, its mighty surges silenced for ever in their strongest heaves. Deep chasms are the scars of those early conflicts; but the atmosphere has smoothed the rugged harshness of the outline of this mighty ruin. Gray lichens, and green moss, and waving grass, and shadowy forest trees have successively appeared upon the hard rock, till the gentle slope of green lawns, and the round swell of grassy hills have taken the place of pointed pinnacles and dreary chasms without the atmosphere, every fracture would have retained its original sharpness. Great splinters of rock; deep angular rifts in the globe's stony crust; desolate rivers of lava, would alone break the dreary monotony of the surface. The mellow haze of autumn; the dewy lustre of spring; the shimmering glare of summer; the white glitter of winter, would be alike impossible. The soft, ethereal purple of the distant mountain, and the unspeakably beautiful lights and shadows which make it look like a dream of fairy-land, would be unknown. The evening pomp of gorgeous clouds; the growing glory of the morning; the ruddy glow of the snow-capped mountain, as it kindles its unconsumed holocaust of light on its lofty altar, could not exist. All the soft shadows and middle tints of objects would vanish. A harsh, unpleasant glare would meet us as we faced the sun; a black night would receive us as we turned from him. This bright blue firmament, with all its loveliness, would pass away, and we would have only a jetty dome bending over us.

Sounds, too, would be banished from this dreary ball. The melody of birds; the slumberous bass of the waterfall; the sighing of winds; the roar of ocean would be over. No aerial waves, dashing in soft breakers upon our ear-drums, would convey to our spirits intelligence of the outer world. No sweet music could clamber up the silent staircase of the ear; no words of love could stir the still depths of the heart. The melody of bells, with all their changeful voices, could no longer speak to the human soul; and all the sweet associations that hover round

accustomed sounds, would die in the bleak desolation. No organ tones could wake devotion; no choral voices could ascend in prayer or praise to heaven; silenced alike the wailings of the Miserere, and the exultant harmonies of the Te Deum.

Life, too, would be impossible, and the blasted globe would reel through space, an accursed desert-blind, deaf, dumb and dead.

ART. VII.-PARTY LEADERS. Sketches of Thomas Jefferson, Alexander Hamilton, Andrew Jackson, Henry Clay, John Randolph, of Roanoke. By Jo. G. BALDWIN, author of "Flush Times of Alabama and Mississippi." New York: published by D. Appleton & Co., 346 & 348 Broadway; London: 16 Little Britain. 1855.

"THE design of this work," says the author in his preface, "is to give some account of the prominent events, and of some of the eminent personages, connected with the political history of the United States." "The events," he says in another part of the same, "are matters of familiar history. All that the writer has attempted has been a concise narrative of the facts, grouping them together in a compact and perspicuous shape, and with such reflections as seemed to him to be just and appropriate. If he has succeeded in this, and in giving to his narrative a fresh and attractive form, his object has been accomplished."

No one, we think, who reads Mr. Baldwin's book, will be of any other opinion than that he has been eminently successful in the modest purpose with which he set out. He has presented as many facts in a small space, in as luminous an arrangement, and in a style as vivid, sparkling and beautiful as any author whose work we have seen for some time.

The book begins with some remarks on the "American Revolution-its general character-its leaders." The author then proceeds, after the manner, and with the object, marked