PROSPECTUS.-This work is conducted in the spirit cf | now becomes every intelligent American to be informeu ittell's Museum of Foreign Literature, (which was favorably received by the public for twenty years,) but as it is twice as large, and appears so often, we not only give spirit and freshness to it by many things which were excluded by a month's delay, but while thus extending our scope and gathering a greater and more attractive variety, are able so to increase the solid and substantial part of our literary, historical, and political harvest, as fully to satisfy the wants of the American reader.

Of all the Periodical Journals devoted to literature and science which abound in Europe and in this country, this has appeared to me to be the most useful. It contains indeed the exposition only of the current literature of the English language, but this by its immense extent and comprehension includes a portraiture of the human mind in the utmost expansion of the present age. J. Q. ADAMS.

LITTELL'S LIVING AGE.-No. 235.-18 NOVEMBER, 1848.

From the British Quarterly Review. 1. Chemistry, Meteorology, and the Function of Digestion, considered with Reference to Natural Theology. By WILLIAM PROUT, M. D., F. R. S., Fellow of the Royal College of Physicians. Third Edition. London, 1845.

2. Actonian Prize Essay. Chemistry as exemplifying the Wisdom and Beneficence of God. By GEORGE FOWNES, Ph. D., Professor of Practical Chemistry, University College, London. London: John Churchill. 1844.

THE recent appearance of a new edition of Dr. Prout's "Bridgewater Treatise," and the publication, not long before, of the "Actonian Prize Essay," induce us to think that the present is not an unsuitable occasion for showing that chemistry is not behind the other physical sciences in rendering service to natural theology. It is not likely that for some time we shall see a new discussion of chemistry in this relation, nor shall we readily find more accomplished chemists than the authors of the works placed at the head of our article. Dr. Prout is one of the most distinguished of our senior chemists, and Professor Fownes one of the ablest of the juniors. The former furnishes the results of the investigations and meditations of years; the latter, himself an original observer, brings to the discussion an accurate acquaintance with the most recent discoveries. Both are able writers, but their works are much more valuable as treatises on chemistry, than as discussions of its bearing on theology. On this we shall have somewhat more to say, further on, but meanwhile we propose, without subjecting these works to detailed criticism, to endeavor to give our readers some conception of the way in which chemistry assists, as well as perplexes, natural theology.

An argument of a twofold kind is deducible from chemistry, in proof of the existence of a great Designer and an Omniscient Chemist. In its one aspect, it considers matter as displaying the characters of what, for want of a more dignified and equally appropriate term, we must call a "manufactured article." In this respect, it seeks to show, that the properties of chemical substances are regulated by laws most uniform, most simple, and harmonious; and proceeds thereafter to infer that there must have been an Author of all this uniformity, simplicity, and harmony; and that these are reflections of similar attributes of his own being. The scope of this argument excludes entirely from notice any relation which may subsist between the properties of chemical substances and the welfare of living beings whose bodies are fashioned out of them, and whose life may be compatible only with the properties which are found to exist. It professes, from a consideration of the qualities of matter, apart from all uses to

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which that matter may be put, to show that it owes its existence and attributes to the will of a Great Creator, and that it proves him to be "excellent in counsel, and wonderful in working." Into this, which is the more limited and more difficult part of the chemical argument for a God, we do not propose, on this occasion, to enter. It would require an amount of space in the mere enunciation of the purely physical facts, on which the theological argument should afterwards be founded, such as we cannot at present command. Nor could the discussion be easily made to run so, that the great mass of our readers should follow it with pleasure, and leave it with profit. We shall not, accordingly, pursue it at all.

The other and more familiar form of the argument from chemistry for the existence of a Creator, is that which considers this science not as complete in itself for that purpose, or as sufficient when taken alone, to supply proof that there is a God; but as acquiring significance for that end only when taken in connection with the living beings (plants, animals, and men) which are indebted to it for the elements of their frames, and beholden to it for the maintenance of those functions, the arrestment of which brings life at once to a close.

The atmosphere, for example, which we shall select as the text whereon to discuss the limits and kind of assistance which chemistry lends to natural theology, is a mixture of oxygen, nitrogen, carbonic acid, water-vapor, and ammonia, which, considered in itself, would not be looked upon by most persons as good or bad, as directly supplying evidence of the absence or the presence of design. But when we consider it in connection with the fact, that every living being on the dry land is bathed in it, and lives on it, and by it, and that those that are in the sea drink it in, dissolved in the element in which they live, then certain conclusions force themselves upon us, concerning the cause why it proves so exactly suited to the necessities of all the animated beings for whom it is the breath of life.

With a view to put the question before us in the clearest light, we shall suppose that it had pleased God, after creating and fashioning this globe, and fitting it for the residence of living beings, to have himself abstained from adding to it an atmosphere, but, as a mark of favor, to have commissioned one of his angels to do so. Let this angel be further supposed to have been a most accomplished anatomist, botanist, physiologist, and chemist, and to have had the chemical elements and their compounds entirely at his command, so as to have been free to make any use of them he pleased.

To our angel philosopher the following task is

assigned:-To furnish an atmosphere fitted to | although the other conditions of life were present, maintain in full vigor the life and health both of the animal would perish from cold.

compound, there was but one that possessed the necessary properties-namely, oxygen. The other gases, moreover, would be excluded by him, not because they were deficient in single serviceable

plants and animals. This atmosphere must, fur- Upon reflection, it would soon be apparent to our ther, be of such a nature that neither class of liv-angelic chemist, that of all the gases, simple or ing beings shall impair its suitableness for the other, but, contrariwise, shall be a powerful means of preserving it in a salubrious state for the opposite class the plant constantly adding to it food for the animal, the animal constantly supply-qualities, but because each one of them was, on ing food for the plant. Moreover, it must be as several grounds, quite inadmissible. nearly as possible quite uniform in composition, and as pure in one direction as in another, and must contain within itself a power of self-purification, so as to be able to remove or destroy all substances injurious to animal or vegetable life, which may find their way into it. This much settled, our angel proceeds to work in the selection of ingredients for an atmosphere. In the first place, he is aware that neither plants nor animals can live or grow for any length of time in darkness, but must be exposed (speaking generally) for at least some twelve out of every twenty-four hours to the influence of light. No dark-colored gas, then, which would absorb and extinguish the sun's rays in their passage towards the earth, can be admissible as a permanent constituent of the air. The ruddy-brown nitrous acid and bromine, accordingly, the purple-vapored iodine, and yellowish green chlorine, are all, on account of their color, even if not otherwise objectionable, quite out of the question.

Thus, chlorine, bromine, iodine, and nitrous acid possess color, odor, taste; are too soluble in water; cannot combine with carbon, and, in addition, are deadly poisons. Carbonic acid and sulphuretted hydrogen, with the exception of color, have all the noxious qualities of those gases also. Hydrogen, the carburetted hydrogens, and carbonic oxide, are too sparingly soluble, and cannot unite with carbon and hydrogen; carbonic oxide, moreover, is a poison, and all have the serious objection of being combustible in oxygen. Of all the gases, there is but one that can for a moment be compared with oxygen-viz., nitrous oxide, or laughing gas. It has the objection, however, of having both an odor and a taste, and of being exceedingly soluble in water and in saline solutions. But what is worst of all, though it may be respired for a short time, not only without inconvenience, but even with pleasure, its continued inspiration occasions violent excitement, and ultimately death.

It appears, then, that oxygen is the only gas In the second place, the gas must be tasteless which will serve to maintain the life of animals. and inodorous; for neither plants nor animals can It is transparent, colorless, tasteless, and inodorexist, unless for a short period, in any of the odor-ous; has a medium solubility in liquids; combines ous or sapid gases. Chlorine, bromine, iodine, with carbon and hydrogen, and evolves heat in so and nitrous acid are on this account again excluded; and so are all the gases, simple and compound, excepting oxygen, nitrogen, hydrogen, and perhaps some of the compounds of carbon and hy-first place, to construct his atmosphere, so far as drogen.

In the third place, the gas or gases of the atmosphere must possess a considerable solubility in water and saline aqueous solutions, for they must be able to become liquid in the blood to produce certain changes there; and to dissolve in lakes, rivers, and the sea, so as to maintain the respiration of the animals living in them.

doing. We may suppose our angel, accordingly, (whom we assume to be an accomplished philosopher, but not an omniscient one,) proposing, in the

animals were concerned, entirely of oxygen. But on making trial of it, he finds that, if taken alone, it proves too stimulating. The actions of the body go on with undesirable rapidity; much more heat is evolved than the animal requires, it passes into a state of excitement and fever, and if allowed to breathe the undiluted gas, speedily perishes. On the ground, The indispensable oxygen, then, must be diluted then, of their sparing solubility, nitrogen, hydro-to the strength proper for animal respiration, by gen, and carbonic oxide must be excluded. On some bland, innocuous gas; and there cannot be a the other hand, the solubility must not be very moment's hesitation as to where that gas will be great, otherwise the blood will be supersaturated, found. The colorless, tasteless, inodorous, scarceand prove too exciting, and the bodies of water on ly soluble, incombustible, negative nitrogen is the surface of the earth will dissolve too much, clearly the diluent required; and we may suppose and thereby come to be hurtful to their inhabitants, a series of trials leading our angelic atmospherewhilst they rob the atmosphere of too large a por-maker to the conclusion, that, though the proportion of its vital ingredients. On this account, then, tions might vary to some slight extent, in the one as well as on others, chlorine, bromine, nitrous direction or the other, without causing the immeacid, carbonic acid, and nitrous oxide must all be diate destruction of animals, sustained life was excluded. compatible only with the respirable mixture conIn the fourth place, (not to enumerate at too taining four fifths by volume of nitrogen, and one great length the qualities desirable in a respirable fifth of oxygen. Animals in lakes, rivers, and the elastic fluid,) the gas or gases to be breathed by sea, having cold blood and a sluggish circulation, animals must be able to unite with carbon and hy-may have more oxygen than those breathing air drogen, and to evolve heat in so doing, otherwise, by lungs, but it is not necessary to make a special

additional provision for them, as it is secured by the circumstance that oxygen dissolves in water to a greater amount than nitrogen does. Wateranimals are, by this simple device, supplied with a more oxygenated air, suited to their peculiar condition.

treme alternations of heat and cold, which would occur on a naked globe. Our atmosphere equalizes, more or less, the temperature of the earth, as in small islands like Madeira, lying far out in the ocean, the climate is rendered equable by the mass of water surrounding it, which cools it in summer and warms it in winter. We do not desire to affirm that it was necessary that our atmosphere should have neither more nor less than the bulk it possesses, in order to temper our climate. It would be very difficult to find data from which to decide positively on this point. All that we say is, that it was requisite the volume of air should be considerable.

Secondly-A mass of atmosphere was necessary, that there might be considerable refraction of the solar rays, and a corresponding scattering and diffusion of the light, heat, and other agencies of the sunbeam; otherwise, certain essential conditions of animal and vegetable life would not be fulfilled.

It may here be asked by some thoughtful person, if nitrogen plays no other part in reference to animal respiration than to dilute oxygen, might not the same end have been equally well gained by diminishing the respiratory organs of animals, so as to have had them four times smaller in capacity than they are? They would then have been filled at each inspiration, with one fifth of the volume of air which at present enters them, so that the atmosphere might have consisted entirely of oxygen. In reference to such a suggestion we would observe, in the first place, that we have no right to assume that nitrogen is of no use to an animal, merely because we cannot show that it is of service; and secondly, that such is the balance of organs in a Thirdly-A large volume of air was required, in living creature, that the dimensions of one could order that great winds might be produced in it, by not be altered without requiring an alteration in the the rarefying action of the sun's rays, and the revsize or capacity of all. If we alter the lungs, we olution of the globe round its axis. We need not must alter the heart, the blood-vessels, the nerves stop to remind the reader how these winds bring -indeed, the whole animal. Now, without enter- us clonds, and carry them away, waft us fertilizing ing into minute discussion, we may suppose, that showers, and when they are too abundant, sweep on the whole, even so far as the animal alone is the earth dry again; how they plough up the deep, concerned, it might be better to dilute the oxygen and refresh all living things there; how they transby a negative gas, and so maintain the bulk of the port man and other animals over the sea, and in a animal considerable, than to give it undiluted oxy-thousand other ways are ministers of good.. gen to breathe, at the expense of dwarfing and altering its whole organism. Moreover, we are not entitled to assume, that oxygen given alone, would have the same effect as that gas mingled with four times its volume of nitrogen. In all probability, it would not. We are not called upon, however, to enter into these discussions, but are entitled, on the other hand, to protest against any such suggestions being made as we have for a moment turned aside to consider. In such an argument as the one we are pursuing, we must either accept the animal as we find it, and consider whether or not the constitution of the atmosphere harmonizes with its necessities, or accept the atmosphere as it is, and ask whether the animal is so constructed as to live within it. We are at present, however, discussing the subject solely as chemists; it is quite competent for us to suggest, if we can, improvements on the atmosphere, but we are not at liberty to change the structure of the animal.

Now, it would have been (so to speak) a waste of force to have made the mass of the air of a gas having powerful chemical affinities, seeing that these are not needed; an inert, elastic fluid, susceptible of vibrations and undulations, being all that is required. This, however, is to say too little; any of the readily combining gases would have been positively prejudicial. We have already seen that the air could not have had its volume increased by addition of oxygen, for that would have poisoned the animals. Moreover, it would have corroded the rocks at the earth's surface; oxidized every oxidable body; and wasted all things. To the other elastic fluids still greater objections apply. No gas would do half so well as nitrogen, for increasing the mass of our air without altering its properties otherwise than by dilution. What water is among liquids, in blandness, neutrality, and indifference, nitrogen is among gases.

On the whole, then, we may suppose our angelNeither, perhaps, is it impossible to indicate pos- chemist, after such a balancing of considerations as itive benefits which flow to all nature from the pres- we have been discussing, and not being at liberty ence of nitrogen in the atmosphere. We would to alter the constitution of the animal, satisfying venture to suggest, in the face of those constant himself that the best possible atmosphere he could declarations, that no use can be found for it-that mingle for sentient living beings would be one conit was necessary for the welfare of animated beings sisting chiefly of nitrogen, and with a fifth of its that the mass of the atmosphere should be consid- volume of oxygen. crable, and this for many reasons; among the rest for these three :

Having, then, provided for the welfare of the animal, our angel turns to the plant. It appears First-Because the vicissitudes of temperature at that the latter requires, speaking generally, four the earth's surface would be much greater than substances to maintain its growth; namely, certhey are, and, in truth, would be incompatible with tain inorganic salts, which, in general, it obtains life, if there were no atmosphere to temper the ex- from the soil; water, ammonia, and carbonic acid,

which it looks for, from the atmosphere. Sup-ygen, hydrogen, and nitrogen, and all oxidable, plied with these, it asks no other food, whether they will be converted into carbonic acid, water, moss or oak-tree, but with its wonderful and quite and ammonia, and do service instead of harm. If inimitable chemistry, transmutes them into hard any soluble inorganic bodies find their way into wood, green leaves, and beautiful flowers. the air, they will be carried down again to the earth by the rain when it falls. And insoluble inorganic substances, being none of them volatile, cannot be raised into the atmosphere.

A certain proportion of water-vapor, then, (which, in truth, is as necessary for the animal as for the plant,) must be added to the atmosphere; likewise carbonic acid and ammonia. The quantity of the two latter will be determined by the number of the plants which are to grow at the same time on the surface of the earth. Let us in the meanwhile, however, not to complicate the problem, suppose the question of quantity left out of sight, and be content with an atmosphere, in which a certain unspecified number of plants and animals may live together.

It remains to ascertain that neither class of living beings shall injure the atmosphere for the other. The problem, however, is found to solve itself.

All this, then, being foreseen, we may suppose our angel-atmosphere-maker about to mingle the ingredients we have named, when it suddenly occurs to him that such a mixture as he proposes to make, will not remain homogeneously mingled, however thoroughly its ingredients may be at first incorporated.

With the properties of individual gases he is fully acquainted, but not with all their actions on each other. He knows, however, that all kinds of matter obey the law of gravitation, and that liquids which do not act chemically on each other, arrange themselves according to their relative densities. If it should be so with gases-and why should it not?-what will become of his atmosphere? The carbonic acid will descend dry, and poison the parched up plants and animals. The oxygen will float in a layer above it, the nitrogen above that, and far out of sight, the watery vapor will form an encircling zone, above which any stray hydrogen, or other light gases, which are thrown into the air, will arrange themselves in thin concentric spheres. In such an atmosphere, not to mention other peculiarities, every object on the earth's surface which reflected light, would be mirrored in fantastic images, like those of the mirage and the fata morgana, at the lines where the different strata meet.

The oxygen which the animal breathes, it converts into carbonic acid, and water, and returns as such to the atmosphere. These the plant appropriates, disposing of the water to suit its own exigencies, making no use of the carbonic acid during darkness, when it sleeps, but drinking it in at every pore as soon as daylight awakes it, taking from it its carbon, and returning its oxygen to the air. There is no accumulation, then, of carbonic acid in the atmosphere, which would kill the animal, for the plant destroys it as fast as it forms. Neither is there accumulation of oxygen, which would ultimately slay both plant and animal, for the latter consumes that gas as quickly as the former supplies it. As for the ammonia, no additional device is needed to furnish it for the plant. All the goodly chemical contrivance already reThe animal supplies it, as well as, in part, the corded seems likely, then, to go for nothing. The carbonic acid. During life, the animal is evolving problem proposed to our angel he cannot solve, ammonia, which reaches the atmosphere, and nour- with the data which we have supposed furnished ishes the plant; and when the former dies, in re- to him, and he returns to the great Creator, to turn for feeding, directly or indirectly, on the veg-confess, that whilst that universal law of gravitaetable during life, it leaves it a legacy of its flesh, tion relentlessly rules all things, he must be foiled blood, and bones, converts itself into carbonic acid, in every attempt to clothe the earth with a respirwater, and ammonia, and leaving its inorganic salts able atmosphere. in the soil, to be appropriated by the roots of the plant, ascends into the air, and feeds it through its leaves.

All this our angel foresees, and also that there shall not only be a constant mutual dependence between plants and animals, but likewise a balance as to relative numbers. For, if the plants shall strive to outgrow the animals, they will be stopped by a deficiency of carbonic acid and ammonia to maintain them; and if the animals shall seek to outstrip the plants in number, they will be poisoned by the accumulation of carbonic acid and the deficiency of oxygen. Each class, then, of living beings will control the other, and maintain its own privileges.

As to further provisions for maintaining the purity of the atmosphere, it appears, on reflection, that none are needed. If any organic bodies are carried up into it, being compounds of carbon, ox

The reply of the Author of all things we may suppose to be, that the law of gravitation, though wide in its bearings, is not universal, but can be suspended or overruled by other laws, when its operation is inconvenient or hurtful to the creatures who live under its influence; and that its action being prejudicial in the circumstances supposed, another law takes its place. Our angel is instructed, that though gases gravitate like other forms of matter, and exhibit greater differences among their relative weights than either solids or liquids do, nevertheless, when they meet, each acts as a void or a vacuum to the other, and they intermingle completely so that not only will any number of elastic fluids, if once mixed, remain homogeneously mingled, but every gas or gaseous mixture possesses a power of diffusing equally through itself any new gas added to it. The problem of a respirable atmosphere is now solved: