SALSES. 219 



The uniformity of the phenomena which are presented in 

 the various stages of their activity, by the salses, mud vol- 

 canoes, and gas-springs on the Italian peninsula, in the 

 Caucasus and in South America, is manifested in enormous 

 tracts of land in the Chinese empire. The art of man has 

 there from the most ancient periods known how to make use 

 of this treasure ; nay, even led to the ingenious discovery of 

 the Chinese rope-boring, which has only of late become 

 known to Europeans. Borings of several thousand feet in 

 depth are produced by the most simple application of human 

 strength, or rather of the weight of man. I have elsewhere 74 

 treated in detail of this discovery, and also of the " fire 

 springs," Ho-tsing, and "fiery mountains," Ho-schan, of 

 Eastern Asia. They bore for water, brine-springs, and in- 

 flammable gas, from the south-western provinces, Yun-nan, 

 Kuang-si, and Szu-tschuan on the borders of Thibet, to the 

 northern province Schan-si. When it has a reddish flame, 

 the gas often diffuses a bituminous odour ; it is transferred 

 partly in portable and partly in lying bamboo-tubes to re- 

 mote places, for use in salt-boiling, for heating the houses, or 

 for lighting the streets. In some rare cases supply of 

 carburetted hydrogen gas has been suddenly exhausted, or 

 stopped by earthquakes. Thus we know that a celebrated 

 Ho-tsing, situated to the south-west of the town of Khiung- 

 tscheu (latitude 50 27,' longitude 101 6' East), which was 

 a salt spring burning with noise, was extinguished in the 

 thirteenth century, after it had illuminated the neighbour- 

 hood from the second century of our era. In the province 

 of Schan-si, which is so rich in coal, there are some ignited 

 carbonaceous strata. Fiery mountains ( Ho-schan) are distri 

 buted over a great part of China. The flames often rise to a 

 great height, for example, in the mass of rock of the Py-kia- 



<" 4 Humboldt, Asie Centrale, t. ii, pp. 519 540; principally from 

 extracts from Chinese works by Klaproth and Stanislas Julien. The old 

 Chinese rope-boring, which was repeatedly employed, and sometimes 

 with advantage, in coal-pits in Belgium and Germany between 1830 and 

 1842, had been described (as Jobard has discovered) as early as the 

 17th century, in the Relation of the Dutch Ambassador, Van Hoorn, 

 but the most exact account of this method of boring the fire-springs 

 (Ho-tsing) is given by the French missionary, Imbert, who resided so 

 many years in Kia-ting-fu (see Annales de la, Propagation de la Foy, 

 1829, pp. 369381). 



