Imatges de pàgina

immersion could scarcely be endured for a few seconds. The water is pure and tasteless, and is used for all domestic purposes. Nothing resembling a deposition is any where observable; nor are its banks or channel at all discoloured. The hill, from the foot of which it issues, has no remark able appearance; at least, there is none of that black pon. derous iron ore, or earth, noticed at the Zwarteberg baths. At the distance of about 300 yards from the source, two bath-houses have been built over the stream, the heat of which, even here, is almost greater than can be borne by a person not gradually inured to it. Between the spring and the bath, where the stream has run a sufficient distance in the open air to allow it time to become a few degrees cooler, the bottom of the rivulet is covered with a beautiful seagreen conferva, waving gracefully beneath the water, like long tresses of hair. Specimens of rocks from this district, sent me by Dr. Smith, show that the waters of this spring issue from quartz rock, containing grains of white felspar in the state of porcelain earth.

Warm Bath at Zwarteberg.-This is a short mountainous ridge, running east and west, and of secondary height. From the lower part of its southern front projects a small flat hill, out of the upper part of which issue, in several places, hot springs, the waters of which raise the thermometer to 118° of Fahrenheit. The water deposites, in the channels along which it runs, an orange-coloured ochre of iron; but, after a course of 200 or 300 yards, ceases to discolour the ground. It contains iron and sulphur, and hence has a slightly chalybeate taste. Within three yards of these hot springs there rises another, the water of which is pure and tasteless, but is not warmer than that of the common springs of the country. Probably the springs here, as at Brand Valley, issue from quartz rock. În the vicinity of the springs, as I observe by inspection of specimens from Dr. Smith, bog-iron ore occurs.

Warm springs also occur in the valley of the Western Elephant River; others near the Eastern Elephant River, in Kamnasi Land; and a third behind Kokman's (Kogman's) Kloof; but all are of lower temperature than those of the Zwarteberg and Brand Valley. There is also a warm spring on the northern side of the Gariep, in Great Namaqualand.

Springs of mineral waters, of the common temperature, have been noticed in various places; one near Graaf Reynet, and another not far from Uitenhage, and one also in the Tarka; but their chemical composition has not been accurately, ascertained.

Remarks on the Importance of a Knowledge of the Natural History and Chemical Composition of Springs. -The springs of the African continent have hitherto been almost entirely neglected by travellers and naturalists, either through indifference or ignorance. Now, however, that scientific men have settled in different parts of that quarter of the globe, particularly in Southern Africa, accurate details may be expected in regard to their various kinds, whether temporary, perennial, intermittent, periodical, spouting, sublacustrine, subfluvian, or submarine; their magnitude and colour; the temperature of common springs, at different elevations above the level of the sea, and during different seasons of the year; and the range of temperature of warm and hot springs. But in order to complete the history of the springs of the country, we must, besides, describe not only the rock or rocks from which they flow, but also ascertain the various relations of these rocks to those of the neighbouring mineral formations. Chemical investigations will afford the 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 spe culation; 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

e earth is composed. Lastly, win 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 th equator to the Straits of Babelmandeb has never bee visited by any geologist.


From the preceding details it results,

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

2. That notwithstanding its nearly insular form, its ex tent 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 civilization of the negroes (if that interesting race be not estined to extirpation, as has been the fate of the abori


gines 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 dis tributed: 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. That no active or extinct volcanoes have hitherto been met with.

10. Lastly, that Africa is less frequently agitated by earthquakes than the other continents.


Natural History of the Quadrupeds of Africa.*

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

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,

[merged small][ocr errors][graphic]
[ocr errors][ocr errors][ocr errors]
[ocr errors]

Group of African Animals.-In front, in the centre, the Rhinoceros; to the right, the Hippopotamus and Orang-outang. In the centre back ground, the Giraffe; to the left, Antelopes and Zebra.-[p. 290]


« AnteriorContinua »