NATURAL DECOMPOSITION. THE fallen leaves decaying on the ground, the mouldering ruins, the crumbling rocks, even the revolting spectacle of animal corruption, and every other variety of form in which the "all-destroying hand of time" indicates decay and seeming annihilation, so far from really tending to weaken the position we are endeavouring to establish,* may be brought forward to strengthen and support it. In the first place, let us consider what takes place on the decomposition of vegetable matter. The principal substances of which all vegetables are composed are, hydrogen, oxygen, and carbon. Though the different species of vegetables that have been discovered exceed sixty thousand, they are all composed of the same, or nearly the same ingredients, in different proportions. In some vegetable products, indeed, which possess very different properties, these proportions vary in so trifling a degree, as to be scarcely distinguished by chemical analysis; and it is impossible to conceive how such important variations in the characters of compounds, so nearly approaching each other in their composition, can be produced. Starch, gum, and sugar, for instance, are vegetable products of very distinct characters; yet the analysis of each affords the same ingredients, and in proportions differing only in the most trifling degree. In living vegetables the carbon is disseminated through the plant in all the ramifications of woody fibre, and it is also mixed with the hydrogen and oxygen in forming the juices that circulate through the leaves and branches. The decomposition of vegetable matter is caused by the separation of the oxygen, hydrogen, and carbon of which it is composed, from their existing combinations, and by their combining, in different proportions with the same, or forming an union with other elements. Vegetable matter, when thus decomposed, becomes the nutriment of other plants, and contributes to the neverending renovation of nature. When the genial warmth of summer, that enabled the noble oak of the forest to secrete and raise its sap, is withdrawn, the tree sheds its leaves on the ground, where they decay and seem to perish; but, ere the returning warmth renews vegetation, those leaves are converted, by new combinations of their elements, into rich manure, and, probably some portion of That there is no annihilation. them will again contribute to the growth and support of their parent tree. When in the course of years, the mighty oak itself falls to the earth, and the returning summer no longer brings with it renewed foliage to the decayed trunk, which lies gradually rotting on the ground, even then, the process of decay is but a more extended process of renovation; and when the action of the air shall have crumbled the timber into dust, it will form a portion of the soil, whence other trees will derive their nourishment. Not one particle of the matter is lost in these changes. It is true, we cannot reproduce the plants in the same form: it surpasses human skill to construct a tree, or to mould the smallest of its leaves; but the elementary substances of which they are composed can be proved to exist, undiminished and unaltered by decay and decomposition. We are enabled to ascertain that the elements continue unchanged; but of the manner in which they are again employed in the formation of other organized beings, we are equally ignorant as we are of the modes by which the Author of nature first called them into existence; though of the fact that the disorganized elements remain uninjured, and are again employed in the organization of other living beings, we possess the most conclusive evidence. The decomposition of inorganized bodies by the hand of time, generally occupies too long a period to enable us to investigate the results of the process, with a view to ascertain whether any of the particles of matter have been lost; but, from a knowledge of the results attending experiments producing more rapid decomposition of the same matter, we may safely draw the conclusion that the decompositions of time, like those of art, are merely the effects of a different arrangement of the elementary particles composing the decayed bodies. When a piece of iron, for instance, is reduced to rust by the action of acids, we can determine, from the product of the decomposition, that the iron, instead of being destroyed, has its weight increased by the absorption of oxygen, and that not a particle of the metal has been lost by the process. If, then, we perceive a piece of iron corroded by long exposure to the atmosphere, and nearly eaten away with rust, we conclude that the same chemical attraction, which was exerted to decompose the water of the acid, and caused the oxygen to unite with the iron, has been operating, in a G the effect of the putrefactive process, like that of all other chemical actions, is only to produce a change in the combinations of the elements on which it operates. This change in animal matter appears to be caused, in the first instance, by the absorption of moisture from the atmosphere, and the decomposition of the moisture absorbed, by the aid of heat. The process of fermentation then commences; the gelatinous and mucilaginous solids are resolved into fluids, and the multitudinous compounds are brought to slower degree, in decomposing the moisture of the atmosphere, and in reducing the iron to an oxide, that has crumbled away, and left scarcely any of the iron remaining in its metallic state. In the latter, as in the former case, we infer that no portion of the metal has been lost; and we feel persuaded, that if the crumbling particles of the corroded iron could be collected, and restored to a metallic state by the expulsion of the oxygen, they would be found to equal the original quantity of the metal before decomposition. The decomposition of animal sub-gether in a condition favourable for the destances is attended with phenomena of a more disgusting character than those accompanying the decay of inanimate matter; but the evidence it affords, so far as it can be obtained, of the indestructibility of matter, is as conclusive in this apparently annihilating process, as in any other branch of chemistry. Animal substances are, however, so extremely complicated in their compositions, and the affinities of the numerous compound substances that enter into their formation are so difficult to determine, that little is known respecting the chemical actions that regulate the functions of the body. The principal ingredients of which animal matter is composed, are ascertained to be oxygen, hydrogen, carbon, and nitrogen. Of the nature of the latter substance, we have, indeed, scarcely any satisfactory knowledge, though it forms one of the principal constituent parts of many important substances, and, in the shape of gas, constitutes four-fifths of the volume of atmospheric air. With these four elementary bodies various others are combined, and form a number of intricately compound products. In the human body there are secreted upwards of twenty different kinds of fluids, and the variety of solid substances of which it is formed, are nearly equally numerous; therefore the difficulty of detecting the elements of each of these component parts, in their united decomposition, amounts to almost an impossibility: and the revolting nature of experiments with putrid matter, and the danger attending them, have also deterred chemists from investigating the subject. The products of animal decomposition, however, when carefully collected, are found to be equivalent in weight to the aggregate mass before putrefaction; and, so far as the inquiry has been pursued, we have the strongest reason to infer that velopement of the affinities of their respective elements. Various gases are evolved, some of which yield a most fœtid smell; and those portions only of the body remain that are not volatile, and they are dried up in a friable state, and crumble at the touch. That moisture and heat are essential to the commencement of the putrefactive process, is ascertained from the circumstance that animal matter may be kept for an indefinite length of time, when the temperature is reduced below the freezing point: and, again, when dead bodies are exposed to a high temperature, until all the animal fluids are expelled, no putrefaction takes place, and in this state they are frequently preserved for centuries. The effect of charcoal, salt, and other antiseptic substances, in counteracting putrefaction, may be attributed to their absorption of water, or oxygen, and thereby checking the decomposition of the moisture, that would otherwise induce putrefaction. The whole process of putrefactive fermentation is, indeed, strictly a chemical one; and, though we are unable to trace all its causes and effects, yet we know sufficient to enable us to infer that it resembles all other chemical actions, and merely resolves the elements of organic matter into other compounds, whilst those elements remain in every respect unchanged and undiminished. We are thus enabled to obtain, even from the dissolution of the body itself, a corroboration of the evidence of the indestructibility of the elements of which it is composed. When it is asserted that the decomposition of the animal frame, after death, produces only a new arrangement of the particles of matter, and that the elements composing the body remain unchanged and indestructible, it may be objected that the product of the decomposition bears no resemblance to the original body; and that, as the particles of matter cannot be again brought into the same combinations, and arranged in the same forms, the body is in fact destroyed. The organized form, it is true, is destroyed, and cannot be restored by human power. The simplest of organized beings are far too complicated in their arrangement, and too delicately and beautifully elaborate in their parts, for the ingenuity of man to equal; and they afford ample evidence of the supreme wisdom of the Author of nature, by whose power they were formed, sustained, and are destroyed. But we know that the omniscient Creator of all things always operates by the simplest means, and is enabled to construct, out of a very few elements, an apparently unlimited number of compound substances. It is our present object to show that none of those simple elements are destroyed by decomposition: and, though the difference between the compounds resulting from the putrefactive process, and those with which they were combined in the living body, is to us so extreme, that their identity is entirely lost; yet, to the eye of Omniscience, the elements of matter must be visible in every hidden form; and we may presume that, in every change those elements undergo, they appear to him the same.T. C. Bakewell. ON TWO SPECIES OF RHEA, OR SOUTH AMERICAN OSTRICH. IN an "Introduction to the study of Birds," published by the Religious Tract Society, will be found, at page 399, the figure, and some account, of a most remarkable bird from South America, allied to the ostrich, and termed the nandu, or South American ostrich, (Rhea Americana.) Few details, however, of its history are recorded, for little, until within the last two years, was known respecting it; but as recent travellers of scientific acquirements have given us much interesting matter on the subject, and moreover discovered a new species, we deem it but right to fill up our previous account, both by farther details respecting the nandu, and also by a history of the new species, so as to render it as complete as possible. First, then, the nandu. Marcgrave, Molina, and Azara, have each noticed the nandu; and the latter informs us, that it abounds on the borders of the river La Plata, "and is generally seen in the open parts in pairs, though sometimes in flocks of thirty." Here it is hunted by horsemen, who capture or kill it with bolos, or thongs of leather, with stones attached to the ends, and which are very effective weapons. So great, however, is the fleetness of the nandu, that it cannot be easily overtaken. "One day," says Mr. Darwin, (see Narrative of the Surveying Voyages of his Majesty's ships Adventure and Beagle-Journal, vol. iii.,) "I went out hunting, at Bahia Blanca; the men rode in a crescent, each being about a quarter of a mile from the other. A fine male ostrich (rhea) being turned by the headmost riders, tried to escape on one side. The gauchos pursued at a reckless pace, twisting their horses about with the most admirable command, and each whirling the balls round his head. At length the foremost threw them, revolving through the air: in an instant the ostrich rolled over, its legs fairly lashed together by the thong.". man From the same scientific writer, whose journal is replete with information, we learn, that the rhea, or ostrich, as he terms it, is abundant over the plains of North Patagonia, and the united provinces of La Plata. It does not appear, however, to have crossed the Cordillera, though it exists within the first range of the mountains on the Uspallata plain, between six and seven thousand feet of elevation. Vegetable aliment, such as grass and roots, form the ordinary diet of the rhea; but Mr. Darwin has repeatedly seen small parties of these birds visit the mud banks of the shore at low water, and that for the purpose, as the Gauchas said, of catching small fish. When hunted by the Gauchas, to whom, fleet and wary as it is, it often falls a prey, it expands its plumed wings, and, as if making sail, scours along, generally running against the wind. "One fine hot day," writes Mr. Darwin, "I saw several ostriches enter a bed of tall rushes, where they squatted concealed, till quite closely approached." To this he adds the following singular fact, which no one would have surmised, namely, that they are capable of swimming. "It is not generally known, that ostriches (nandus) readily take to the water. King informs me, that at the Bay of San Blas and at Port Valdes, in Patagonia, he saw these birds swimming several times from island to island. They ran into the water, both when driven down to a point, and likewise of their own accord, when not frightened: the distance Mr. arise from the difficulty of several females associating together, and persuading an old cock to undertake the office of incu at first, some degree of association, between at least two females; otherwise the eggs would remain scattered over the wide plains, at distances far too great to allow of the male collecting them into one nest. Some have believed, that the scattered eggs were deposited for the young birds to feed on. This can hardly be the case in America, because the huachos, although often found addled and crossed was about two hundred yards. | When swimming, very little of their bodies appear above water, and their necks are extended a little forward. Their pro-bation? It is evident that there must be, gress is slow. On two occasions, I saw some ostriches swimming across the Santa Cruz river, where its course was about four hundred yards wide, and the stream rapid." The aquatic habits of the rhea have been also noticed by captain Fitzroy, in his narrative. It may here be added, that the emu of New Holland, though not an aquatic bird, swims well. It has been observed by captain Sturt, crossing the Murrumbidgee river. Whe-putrid, are generally whole." May it ther the African ostrich or the cassowary of Java, ever enter the water is not known; with respect to the latter, however, a similar habit is by no means improbable. The male rhea is readily to be distinguished from the female, by his large size and darker colouring. The noise he makes is a deep-toned hiss, which, when Mr. Darwin first heard it, he fancied was uttered by some "wild beast;" "for it is a sound that one cannot tell whence it comes, or how far distant." As is the case with the ostrich, several females lay in one nest; the number of eggs deposited altogether, varying from twenty to forty or fifty. Azara says, even seventy or eighty. Each female lays about seventeen eggs. It is well ascertained, that the male emu alone undertakes the work of incubation. In the instance of the rhea, the same curious fact occurs; the male assiduously broods over the nest; hatches the eggs, and for some time afterwards accompanies the young. "When we were at Bahia Blanca," says Mr. Darwin, "in the months of September and October, the eggs (of the rhea) in extraordinary numbers, were found all over the country. They either lie scattered single, in which case they are never hatched, and are called by the Spaniards huachos; or they are collected together in a shallow excavation which forms the nest. of the four nests which I saw, three contained twenty-two eggs each, and the fourth, twenty-seven. In one day's hunting on horseback, sixty-four eggs were found; forty-four of these were in two nests, and the remaining twenty scattered huachos." The circumstance of the female rhea thus scattering her eggs, instead of depositing them all together, is very remarkable. "It appears odd, that so many should be wasted; does it not not be probable, we would here ask, that to a similar practice, that is, of scattering her eggs, in the case of the African ostrich, the often quoted passage in the book of Job may refer, and which appears to be contradictory to the wellestablished fact, that the eggs in the nest are carefully tended by both the females and the male of the associated party? In Southern Patagonia, a distinct species of rhea exists, Rhea Darwinii, Gould, first described, (from a specimen brought home by Mr. Darwin,) at the scientific meeting of the Zoological Society, March 14, 1837, (See Proceedings, 1837.) It is much less than the common rhea; the bill is shorter than the head, and the tarsi, instead of being broadly scaled in front, are covered with scaly reticulations. The tarsi, moreover, are plumed for several inches below the knee; the wings are more fully feathered, the plumes being broader, and terminated by a band of white. It is to the discoverer of this species, Mr. Darwin, that we altogether owe our knowledge of its habits. "When at the Rio Negro, or Northern Patagonia," he writes, "I repeatedly heard the Gauchas talking of a very rare bird, which they called Avestruz petise. They described it as being less than the common ostrich, (which is there abundOutant,) but with a very close general resemblance. They said its colour was dark, and mottled, and that its legs were shorter and feathered lower down than those of the common ostrich. It is more easily caught by the bola than the other species. The few inhabitants who had seen both kinds affirmed they could distinguish them apart from a long distance. The eggs of the small species, however, appeared more generally known, and it was remarked with surprise, that they were very little less than those of the rhea, but of a slightly different form, and with a tinge of pale blue. "Some eggs picked up on the plains of Patagonia, agree pretty well with this description, and I do not doubt are those of the petise. "This species occurs most rarely on the plains bordering the Rio Negro, but about a degree and a half farther south, they are tolerably abundant. One Gaucho, however, said he distinctly recollected having seen one, many years before, near the mouth of the Rio Colorado, which is to the north of the Rio Negro. They are said to prefer the plains near the sea. "When at Port Desire, in Patagonia, (lat. 48 degrees,) Mr. Martens shot an ostrich, and I looked at it, forgetting for the moment, in a most unaccountable manner, the whole subject of the petises, and thought it was a two-third grown one of the common sort. The bird was cooked and eaten before my memory returned. Fortunately, the head, neck, legs, wings, many of the larger feathers, and a large part of the skin had been preserved. From these a very nearly perfect specimen has been put together, and is now exhibited in the museum of the Zoological Society." It is from this specimen, unique in Europe, that the description referred to is taken. "Among the Patagonian Indians, in the Strait of Magellan, we found a half Indian, who had lived some years with the tribe, but who had been born in the northern provinces. I asked him if he had ever heard of the Avestruz petise; he answered by saying, 'Why there are none others in these southern countries.' He informed me, that the number of eggs in the nest of the petise is considerably less than with the other kind, namely, not more than fifteen on an average; but he asserted, that more than one female deposited them.” The petise is more shy and wary than the common rhea, and distinguishes the horseman at a great distance. In ascending the river at Santa Cruz, few were seen, but more when the party returned, rapidly descending the current. They were either in pairs, or in small parties of four or five. When disturbed, and preparing to run, this species does not, like the other, expand its wing plumes; it however takes as readily to the water, and swims with equal facility. The petise was seen by Wallis at Bat chelor's river, (lat. 53 degrees, 45 min.) in the Strait of Magellan. Dobrizhoffer, in his account of the abipones (1749) also notices it, and distinguishes between it and the common rhea. "Those," he says, meaning the latter, "which inhabit the plains of Buenos Ayres and Tucuman, are larger, and have black, white, and grey feathers; those, the petises, near to the Strait of Magellan, are smaller and more beautiful; for their white feathers are tipped with black at the extremity, and their black ones, in like manner, terminate in white." M. D'Orbigny heard of the petise, and endeavoured, though without success, to procure specimens, while at the Rio Negro. To Mr. Darwin is due the merit of its introduction to science, and all definite details concerning it.-M. THE FIRST OBJECTS OF MENTAL CULTURE. MAN is not an automaton, a simple animal, nor an unearthly being; his instincts are few and feeble; he is gifted with reason and reflection, to guide and govern his purely animal propensities; the manifestations of his mind are enlarged, and he possesses the highest moral sanctions for his control. Moreover, he has the power of determining his own will, and yet this will depends, for its firmness and perseverance, upon the healthy condition of the body in general, and upon the integrity of the brain in particular. Thus, then, to seek for mental developement in man, as a spiritual being only, would be to secure as signal a failure, though not with so fatally injurious a result, as, forgetting altogether the immaterial spirit, to address the exclusive attention to corporeal manifestations. Although it is true that the immaterial principle cannot be subjected to the process of growth and decay, of health and disease, of tension and relaxation, of tone and feebleness; yet it is equally true, that the manifestations of mind can only be recognized through the medium of bodily organization, and that these manifestations may be variously modified by the changing conditions of the corporeal organs, through which they are rendered apparent. Hence, in a mind unaccustomed to distinctions, the bodily mode may be confounded with the spiritual essence; and error in judgment, if not more serious practical mischief, will be the consequence. |