CHEMICAL COMPOSITION OF SPRINGS.

437

necessary details as to the different mineral matters that enter into their composition. The remarkable animal substance met with in some European springs, and probably of more frequent occurrence than is believed, and which may be derived from the strata containing animal fossil remains, through which the spring waters percolate, ought to be looked for, because its presence will afford to the chemist an opportunity of examining a substance of a very curious nature; to the geologist, data for interesting speculation; and to the physician the means of judging of the mode of action of those waters containing it, in scrofula and other diseases in which its use is said to be so beneficial. It may happen here, as in other countries, that the springs deposite around their sources, and at greater or less distances from them, much of the dissolved and suspended foreign matter they contained, and thus give rise to mineral formations, the external aspect and mode of arrangement of which will illustrate geological phenomena observed among the older rock-formations of which the crust of the earth is composed. Lastly, when it is known that hot springs are intimately connected with subterranean igneous agency,—that power which formerly acted so extensively in forming and modifying the rocks of which the crust of the earth is composed, and which even now continues, although on a less extensive scale, to occasion considerable changes on the surface of the earth, their natural and chemical history becomes very interesting from the light they shed over many important geological phenomena.

Geology of Caffraria, Natal, &c.—The geology of the countries of Caffraria and Natal is entirely unknown. In Sofala there are said to be mines of silver; and gold is collected from the sands and gravels of some districts. The kingdom of Monomotapa, as it is called, at the distance inland of about forty days' journey from Sofala, affords gold, topazes, and rubies. The geology of the country from Delagoa Bay, in lat. 26° S., to Cape Delgado, in lat. 10° S., is unknown: a small quantity of gold-dust is collected in it. From Cape Delgado to the equator, the country, which is under the dominion of the Imam of Mascat, is unknown in a geological point of view. The country from the equator to the Straits of Bab el Mandeb has never been visited by any geologist.

CONCLUSION.

From the preceding details it results,

1. That, of all the quarters of the globe, Africa has the most truly tropical climate.

2. That, notwithstanding its nearly insular form, its extent of coast is much less in proportion to its area than in the other quarters of the globe.

3. That the peculiar condition of the human species, the distribution and even the aspect of the lower animals and plants, and many of the characters of the African climate, are connected with its comparatively limited extent of seacoast, its extensive deserts, and arid soil.

4. That from the maritime situation of Sierra Leone and its colonization by Britain, and the connexion of the southern parts of the Great Table-land with the British settlements on the Southern coasts of Africa, we may conjecture that the civilisation of the negroes (if that interesting race be not destined to extirpation, as has been the fate of the aborigines of the New World) will be effected from these two quarters, through the energy, enterprise, and perseverance of missionaries, well instructed in the various useful arts of life, and in the simple and pure principles of Christianity.

5. That its springs, lakes, rivers, bays, and arms of the sea, are fewer in number, and present more uniformity of aspect than is generally the case in other parts of the world.

6. That it is eminently characterized by its vast central and sandy deserts, its great southern table-land, and the vast expanses of Karroo ground.

7. That, of all the rock-formations, those of limestone and sandstone are the most frequent and most widely distributed; that natron, a rare deposite in other countries, is comparatively abundant in Africa; that salt is very widely distributed, though in some districts it is wholly deficient; but coal is wanting. And the precious stones, so frequent in other tropical regions, are here of rare occurrence.

8. That the metals, although met with in different quarters, are nowhere abundant; and that, of all the different metals, gold is the most generally distributed.

9. Lastly, That Africa is less frequently agitated by earthquakes than the other continents.

ZOOLOGY.

CHAPTER XIX.

Natural History of the Quadrupeds of Africa.*

Introductory Observations-Orang-outang-Monkeys-Baboons-Lemurs Galagos-Bats-Shrew Mice-Cape Mole-TenrecRatel-Otter-Jackals and Wild Dogs-Civets-Lion-Panther and Leopard-Lynxes-Squirrels-Marmots-Sand Mole-Gerboa-Rats and Mice-Dormice-Porcupines-Hares and Rabbits-Cape Ant-eater-Manis-Elephant-Rhinoceros - Ethiopian Hog-Hippopotamus-Zebra-Quagga-Camel - Dromedary_Red Deer_Giraffe_Antelopes of various Kinds—Gnu— Cape Buffalo-Egyptian Goat and Sheep.

A KNOWLEDGE of the geographical distribution of animals, and of the laws which regulate that distribution, has excited a considerable degree of attention since the time of Buffon, whose writings may fairly be regarded as the first to create an interest in favour of this branch of natural history. The slight observ

* I think it proper to apprize the reader that in the three following chapters, devoted to the Zoology of Africa, several well-known and interesting species, such as the Egyptian Ichneumon, the Fennec of Bruce, the Sacred Ibis, &c. are intentionally omitted, as being characteristic of certain portions of the African continent, the general history of which does not fall within the scope of the present volume.

In revising the following sheets for the second edition of this work, and after consulting, more particularly, the recent travels of the Messrs Lander to explore the course of the Niger, I have not found it necessary to alter any of the facts or inferences formerly stated in this volume. Messrs Landers' publication, though one of the highest interest and importance both in its general results and its detailed descriptions, is of less value in relation to natural history than to many other branches of human inquiry, from the authors' want of systematic knowledge, and the consequent absence of precision, and of such definite details as might eventually, even in the absence of specimens, have enabled the European naturalists to arrive at some positive results. However, these brave and intelligent men effected so much under circumstances of such difficulty and danger, that we may well wonder rather at what they have actually achieved than at what they have left to be still accomplished.-J. W.

ance of the physical characters and other local peculiarities of countries, which prevailed prior to that period, rendered the precise induction of general views a matter of extreme difficulty; and, as navigators and naval adventurers of every class were indifferent to the accuracy of science, and ignorant of the valuable results which might spring from a more correct record of the localities of species, our knowledge of these localities did not increase in the same proportion as the species themselves. Even at the present day our collections are frequently rendered of little avail for the purposes of zoological geography, by the products of one country being intermingled with those of another thus, the splendidly-feathered tribes of Rio Janeiro are frequently combined with the scarcely less brilliant birds of New Holland and Van Diemen's Land; while the student of Indian entomology labours under a similar chance of error, in finding the Asiatic insects arranged by the merchant along with an additional supply from the Cape of Good Hope. These and other sources of confusion have long retarded our knowledge of the geography of animals.

The habits and dispositions of animals result from their structure, and that structure is invariably adapted to the local circumstances under which they are naturally placed. It must not, however, be supposed that the geographical distribution of species can ever form a proper basis for their zoological classification. Many natural families and genera are so extensively distributed as to be almost equally characteristic of every quarter of the globe. The wolf and the rein-deer are common both to Europe and America; and the lion occurs in the forests of Asia as well as among the African deserts. These, however, are exceptions to the general rule; for it will be found, on examination, that every great continent, or extensive tract of country, though possessed of features which, to a certain degree, assimilate it to those of other regions, is yet distinguished by many characters entirely peculiar to itself, and which constitute its zoological aspect. Thus the kangaroo and the ornithorynchus are characteristic of, because peculiar to New Holland; the lamas and vicunhas are only found in South America; the ostrich and the camelopard are proper to Africa; the lemurs to Madagascar ; the pongo, or gigantic orang-outang, to the great Asiatic islands; and the common toad to the western countries of Europe. So also, in the order of quadrumanous, or fourhanded animals, such as apes and monkeys, the division called Platyrrhini, distinguished by the breadth of the partition which separates the nostrils, occurs only in South America; while

another great division, named Catarrhini, of which the nostrils are contiguous, is found only in the Old World. A naturalist would therefore find no difficulty in determining, merely from a glance at the muzzle, whether a species of this order was native to the ancient continent or the new.

Wherever the observant traveller turns his steps, he finds in every country animals peculiar to itself; and many of these, occupying the most remote and insulated spots, are the most inadequately supplied with the means of locomotion. The mode of their original dispersion, whether from a single position, or from multiplied centres of creation, has therefore been a theme which has not unfrequently exercised the ingenuity of naturalists. The subject, however, seems to be one which scarcely falls within the scope of human intelligence; although a most ample source of interesting and legitimate speculation may be made to flow from an accurate and extended record of facts illustrative of their present distribution, the amount of genera and species, the relation which that amount bears to the animal productions of other countries, and similar numerical details.

In the present chapter, we propose to exhibit a brief sketch of the natural history of the greater portion of the African continent; and, although our limits will not permit us to draw an extended parallel between the zoology of that country and the animal products of the other quarters of the globe, we shall yet have occasion, at an after period of our series, to survey the characteristic features of all the other great divisions of the earth, and, in so doing, may afford the means of an accurate comparison between these and the subjects of our present inquiry. In the mean time, however, we shall not abstain from an occasional reference to the analogous species of other countries, whenever we shall be thereby enabled to throw any additional light upon the history of the African tribes.

Most nearly allied to the human race of all the species of the brute creation, the black or African orang-outang (Simia troglodytes of Linnæus) may be allowed to assume the foremost place in our enumeration. It is a native of no other country than Africa, although we are as yet unacquainted with the extent of territory which it occupies in that continent. Angola, the banks of the river Congo, and all the districts which border the Gulf of Guinea, are the localities in which it has as yet most frequently occurred. Its history, like that of its Asiatic congener, the red orang-outang (Simia satyrus, Linn.), is still involved in considerable obscurity. Its habits, in the adult state, are