SULPHUR AND ITS EXTRACTION. 485 



cale by the miners, and mainly composed of gypsum. This has re- 

 sulted from the oxidation of the sulphur to sulphuric acid by atmos- 

 pheric agency, the acid in turn attacking the lime carbonate, and 

 forming sulphate (gypsum). The most plausible supposition as to the 

 origin of the sulphur-seams would appear to be that the lakes received 

 streams of water containing calcium sulphide in solution, this calcium 

 sulphide probably resulting from a reduction of the masses of calcium 

 sulphate (gypsum) by the action of volcanic heat. Gradual decompo- 

 sition of the calcium sulphide in the presence of water would finally 

 result in a deposition of sulphur and of lime carbonate, in the relative 

 proportions of twenty-four and seventy-six per cent. As a matter of 

 fact, much of the Sicilian ore actually has this percentage composition. 

 Whatever the process has been, it is no longer in activity, and there is 

 no growth nor renewal of the beds, in this respect differing essentially 

 from recent deposits due to " living " solf ataric action. 



Almost all the Sicilian ore is carried to the surface on boys' backs, 

 consequently it does not pay to work below about four hundred feet, 

 as it then becomes necessary to employ hauling machinery. Hence 

 the deposits lying below that horizon are hardly touched, and as many 

 of the beds are nearly vertical, and do not diminish in yield as they 

 descend, the still untouched resources must be very great. Various 

 estimates have been made as to the period for which the supply will 

 last at the present rate of consumption ; these range from fifty to 

 two hundred years. There are said to be about two hundred and fifty 

 mines in the island, and no less than 4,367 calcaroni were reported in 

 operation fifteen years ago. The average yield is stated not to exceed 

 fourteen per cent. 



In the province of Murcia, and at other places, in Spain, the exist- 

 ence of fine beds of sulphur has been ascertained. One is worked by 

 an English association, the Hellin Sulphur Company. The quality is 

 very good. 



A sulphur-deposit exists at Djemsa, in a perfectly rainless desert 

 on the African coast near Suez, very near the sea, and constituting a 

 hill six hundred feet high, whose sides are blasted down as in quarry- 

 ing stone. Some two hundred Arabs, employed under French engi- 

 neers, succeeded in mining ten tons a day. A similar deposit occurs 

 at Ranga, five hundred miles from Suez, also near the coast of the 

 African Continent, which differs only in being buried under other 

 strata, so that mining is necessary. 



The Gunong Jollo, or sulphur mountain of the Sunda Islands, lies 

 southwest of the village Prado, and southeast of Dompo. The sulphur 

 is dug from three places in an old crater now in the solfataric stage 

 of its existence. Each spot is one hundred to one hundred and twenty 

 roods long, and fifty to sixty broad. The sulphur collects between 

 masses of white stone (perhaps decomposed trachyte), and sometimes 

 covers a space of one to three roods square. On the liquid and warm 



