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Paris, is used in combination with oil as a cement for the seams of boats and junks. The Chinese turn it to various other purposes, honest and dishonest. It is sometimes used as a tooth-powder ; but the strangest application of it is as a gruel in fevers, under the idea of its being cooling. Perhaps the persuasion of the wholesome, or at least innocuous qualities of powdered gypsum renders them less compunctious in using that substance to adulterate pounded sugar-candy, which it closely resembles ; and we shall see, in a future chapter, that it serves as one ingredient in converting black teas, which come down damaged to · Canton, into what are sold as green.
The coal at Canton is far from pure; it contains a small proportion of bitumen, abounds in sulphur, and leaves much earthy residuum. The coal-mines by the river were observed to be in the sides of cliffs, rising up directly from the water, and worked by driving a level from the river into the side of the mine, the coal being laden in boats from the mouth of a horizontal shaft. The character given by Du Halde of the coal to the northward throughout the empire is much the same. He says, the fires made from it are difficult to light, but last a long time. He adds, that "it sometimes yields a disagreeable smell, and would suffocate those sleeping near it, but for a vessel of water, which attracts the fumes, so that the fluid becomes charged with them.” This may be the sulphuric acid, for which water has a strong affinity. There can be no doubt of the abundance of coal throughout China, nor of its extensive use ; points which were both proved by the large supplies furnished to the boats of the embassy, and the heaps exposed for sale. The application of this mineral as fuel, so long ago as the end of the thirteenth century, is shown by the following
accurate description of Marco Polo :—He says, “there is found a sort of black stone, which they dig out of mountains, where it runs in veins. When lighted it burns like charcoal, and retains the fire much better than wood; insomuch that it may be preserved during the night, and in the morning be found still burning. These stones do not flame, excepting a little when first lighted, but during their ignition give out a considerable heat." *
From the neighbourhood of Canton to the sea, the rocks are composed of red sandstone resting on granite, until, on reaching the clusters of islands that line the coast, these are found to consist of a coarse granite only, crossed by perpendicular veins of quartz. Over the irregular surfaces of the islands, and at the summits of the highest, are strewn immense rounded boulders of the same rock. They are generally imbedded in the coarse earth, which is a disintegration of the general substance of the islands, and, as this is washed from under them, roll down the steep declivities until they reach a level space, and commonly stud the sandy margins of the islands with a belt of piled rocks, some of them many tons in weight. The scenery of these islands has been often compared to that of the Hebrides, and is quite as barren. A single instance of trap formation was detected by Dr. Abel, at an island visited by the “ Alceste’ frigate with Lord Amherst's embassy on board, and destined one day to be a British colony under the name of Hongkong. “I examined,” he says, “ the rocks by the waterfall, and found them composed of basaltic trap, exhibiting in some places a distinct stratification, in others a confused columnar arrangement.” | Close to this was a mass, insulated by the sea-water, composed of two kinds of
* Quarto edition, page 273. † Abundance of trap rocks have been since found at Hongkong.
rock, granite and basalt, whose junction exhibited some curious facts. A dike of basalt passes upwards through the granite, and spreads over it. It is not in immediate contact with the granite, but separated by three narrow veins which interpose, and follow the dike through its whole length, the width of each not exceeding four inches, while that of the basalt is as many feet. The veins were of three kinds ; first, granite and basalt mixed together in a confused manner; second, pure felspar : third, a sort of porphyry composed of very perfect crystals of felspar in a basaltic base. Some islands near Chusan exhibit basaltic rocks, and many more would probably appear on further investigation.
No active volcano is known to exist in China ; but the line of mountainous provinces which form the western side of the empire, from Yun-nân to near Peking, exhibits what are generally considered as slumbering volcanic symptoms, such as wells of petroleum, salt and hot-water springs, gaseous exhalations, and occasionally severe shocks of earthquake. In Yun-nân there are salt-water wells near Yaou-gan-foo, in latitude 25° 35'; the southwest part of the adjoining province of Sze-chuen abounds in the same : in Shen-sy, near the city of Yen-gân-foo, in latitude 36° 40', there is found petroleum ; and in Shân-sy there are hot-water springs, as well as jets of inflammable gas, said to be employed for the purpose of distilling saline water procured from wells in the neighbourhood. This connexion of the gaseous exhalations with saline springs has been considered as a corroboration of the fact, the same having been observed in Europe and America.* The Chinese are said to convey the gas to the place where it is consumed by bamboo pipes. These are terminated by a tube of clay to resist the action of
: * De la Beche, Geology, p. 132.
the fire; and the combustion thus produced is so intense that the caldrons are rendered useless in a few months. A very severe and destructive earthquake occurred in Sze-chuen, during 1817, and another of the same descrip
tion is remembered at Peking, as having happened in 1731. The slight shocks which have been only just perceived in the neighbourhood of Canton were probably nothing but distant vibrations, communicated from some
portion of that line of active volcanoes which extends from the north-east extremity of Asia through Japan, Loo-choo, Formosa, Luconia, and other islands, to Java.
We may conclude with noticing some of the principal minerals of China not already described. At the head of these must be placed the famous Yu stone, being nephrite or jade, of which was composed the Joo-ee, or emblem of amity, sent by the late emperor to the Prince Regent.
The colour is a greyish white, passing through intermediate grades into a dark green.* “ It is semi-transparent and cloudy, fractures splintery, and is infusible without addition.” † The country in which it is principally found is said to be Yun-nân, where they discover it in nodules within the beds of torrents. This stone is so extremely hard, that the Chinese, in cutting it, use their powder of corundum, sometimes called adamantine spar, as they do in cutting lenses for their spectacles from rockcrystal.† The corundum is met with in granitic rocks, of which it is sometimes a component part. Its specific gravity is about 4, and its hardness very great. From the subjoined analyses, stated in centesimal ratios by Dr. Kidd, it appears that the constituents of corundum, as well as its specific gravity, are nearly the same as those of emery, which is used for the like purpose by European lapidaries. Chinese corundum.
Emery. Alumine .. .. .. .. .. 84.0 Alumine .. .. .. .. .. 80 Silex .. .. .. .. .. .. 6:5 Silex .. .. .. .. Oxyde of iron .. .. .. .. 7.5 Oxyde of iron ....
Residuum .. .. .. .. .. 13 98.0
* A very large specimen may be seen at the British Museum, cut into the form of a tortoise, and found imbedded in the banks of the Jumna
+ Dr. Abel. This is very abundant, and the best comes from Fokien, & Mineralogy, vol. i. p. 153.