these bones, blackened by the carbon which is evolved from their animal matter. Exposure to an open fire drives off this carbon, and leaves the bones still unaltered in form, but nearly and these bones, subsequently reblanched: duced to powder, and mixed with a sufficient quantity of water to give them the requisite degree of consistence, are formed into vessels, which are employed in the process of refining gold and silver. It was stated that, during the destructive distillation of bone, the carbonic acid and inflammable gases are suffered to escape: but of these the latter might be employed in supplying light to gas burners; and then, out of the numerous products of the complicated process which I have been describing, the carbonic acid would be the only substance not employed for some useful purpose. SECT. VII. From Animals as a Source of Clothing, &c. for Man. THE utility of many of those animals which supply us with food does not terminate in merely that adaptation of them to human wants. the same animals we are supplied with clothing also (but this service, indeed, they render to us in common with various other animals which are unfit for food); and, according to the different states of civilization in which mankind exists, that clothing is more or less artificially prepared. Thus while the African or Australian savage scarcely protects his body from exposure by a partial covering of leaves, or the inner bark of trees; and the Esquimaux envelopes his body in the undressed skin of the seal which he has recently killed, supplying also the separate coverings of his head and feet and hands from the same source; the poorest peasant of any civilized part of Europe derives his clothing not only from one but many different species of animals; to say nothing of those occasional parts of his dress which are obtained from the vegetable and mineral kingdom. The ox, the dog, the sheep, the beaver or the rabbit, and the silk-worm, in almost every instance contribute their direct contingent to the apparel of the humblest individual of Europe, who is not absolutely a mendicant: and, with reference to the dress and ornamental appendages of individuals of more elevated rank, to the animals already mentioned may be added the deer, the goat, the camel, the elephant, the ermine, and numerous other animals which supply the various and rich furs of commerce; the ostrich, and many other birds; and even the tortoise, the oyster, and the puny architect of the more beautiful species of coral. Nor are the advantages which mankind derive from the animal kingdom, with reference to ge neral commerce and the arts and economical purposes of life, of less importance than the foregoing. How many different substances, as leather, and parchment, and glue; and what various instruments, either for common use, or ornament or amusement, are manufactured from skin and horn, and bone and ivory! With respect to the last mentioned of which substances indeed, it is a highly interesting fact, that the world has not been supplied with it solely from the two still existing species of elephant, but also, and in a very large proportion, from the extinct and fossil species. Under the name of licorne fossile, the tusks of the extinct species have for ages been an object of commerce in the Russian dominions: and M. Pallas describes the abundance of these fossil tusks to be such, that they are found in every direction throughout the greater part of north-eastern Russia. If we only consider the amount of the consumption of wax and honey, of what importance is not that little insect the bee: and the same observation may be made with reference to the silk-worm and the coccineal! Lastly, for it is necessary to bring the present subject to a close, what immense advantages accrue to commerce and navigation from the traffick in even a very few species of fish, as the whale, the cod, the herring, and the pilchard! so great indeed are those advantages, that the ques tion of the right of fishery on a particular coast has sometimes been the occasion of involving the most powerful nations in expensive wars: for these fisheries, at the same time that they are a source of immense riches to individuals, constitute as it were a nursery for the hardiest race of sailors; and thus become of the highest importance in a national point of view. СНАР. Х. Adaptation of the external World to the Exercise of the Intellectual Faculties of Man. SECT. I. On the Rise and Progress of Human Knowledge. IN the preceding part of this treatise the physical character and condition of man were first considered; and, afterwards, the adaptation of external nature to the supply of his bodily wants. It remains for us to consider the adaptation of the various objects of the material world to the exercise of his intellectual faculties. But, in contemplating the connexion which exists between the external world and the exercise of the mind of man, who shall attempt to describe the nature and boundaries of that yet unmeasured plain of knowledge, in which man is constantly either intellectually expatiating, or practically exerting himself? who, without wandering into the mazes of metaphysical speculation—always amusing in the pursuit, but never, T perhaps, satisfactory in the result-who shall develope the obscure steps by which science first finds access to the mind? In reflecting indeed on the state of civilized society during its earlier periods, there is nothing more wonderful in the intellectual history of mankind, than the skilful management of many processes in the arts, the true nature of which was not understood till ages and ages afterwards. Thus, although zinc was scarcely known as a distinct metal till about a century since; and, almost within the same period, one of its commonest ores, calamine, was held in so little estimation in Great Britain that it was frequently used merely as ballast for shipping, (Watson's Essays, vol. iv. p. 6.); yet that same ore was used before the time of Aristotle for the purpose of making brass, and to that purpose is principally applied at the present day. The process also of making wine was known in the earliest periods of history; although the principles on which it is produced were not well understood till a few years since. Another remarkable fact in the history of human science, which, though frequently observed, has not yet been explained, is the occasional arrest of its progress at a point immediately bordering on discoveries which did not take place till many ages subsequently". This u The substance of the following note, though not directly illustrative of the subject now under consideration, is not irrele |