486 THE POPULAR SCIENCE MONTHLY. 



sulphur a hard crust forms, two inches thick. Digging is only carried 

 on at morning and evening, the heat being too great at midday. 

 Round holes are made, eight to nine feet apart, two feet deep, and 

 with an outlet from above of one foot, and from below of three or 

 four feet. Sulphur is also found in the solfatara of Gunong Prewa, 

 but in trifling quantity. A great deal exists on the sides of Tambora. 



Tripoli possesses a sulphur-deposit important both for extent and 

 richness, but it is not worked. 



In Turkey, native sulphur is found in some quantity adjacent to 

 the lead lodes at Devrent (Derbend), near Alashehr, Salykloe, and 

 Nymphi. A sulphur-mine exists two days' ride from Ai'ta, and four 

 from Butrinto, Albania, and there are other mines near the Darda- 

 nelles and at Alahtan, about six hours from Kassaba. 



In the United States, sulphur is found native in Nevada, Califor- 

 nia, Utah, Virginia, Louisiana, and other States, and occurs in beds of 

 considerable bulk in Uintah county, Wyoming, near Evanstown, where 

 it is said to be quite pure ; also in some quantity in the Yellowstone 

 Park, Montana, and in various localities in New Mexico. It is only 

 worked to any extent in Nevada and California, and even there not on 

 a large scale, the total production in 1880 being stated at under six 

 hundred tons. Locally produced sulphur can not compete in price 

 with imported Sicilian, on account of the cost of land transport ; it 

 is, moreover, found to be often contaminated with arsenic, which 

 greatly reduces its market value and limits its application. At the 

 most important mine, called the Rabbit Hole, in Humboldt County, 

 Nevada, the sulphur occurs as an impregnation in a white volcanic 

 tuff or breccia, of Miocene age. The deposit is worked by regular 

 mining, and the mineral, containing fifteen to forty per cent of sul- 

 phur, is dealt with by the steam process, the production being some- 

 times six tons a day. At the Pluton mines, California, the sulphur is 

 found as a crystalline body scattered through a confused mass of de- 

 composed rocks, and intimately associated with cinnabar, apparently 

 occupying an ancient crater. The mineral is removed altogether, and 

 the sulphur is either recovered by steam process, or, if both sulphur 

 and cinnabar are in paying quantities, the mass is put into a mercury 

 distilling furnace, and the sulphur is separated from the mercury by 

 passing superheated steam into a chamber situated in front of the 

 mercury-condensing chamber. 



Sulphur is extracted from the earthy materials with which it is 

 intimately associated in nature, by the following several means : 1. 

 Dry heat (roasting the ore in mass) ; 2. Wet heat (melting out by 

 the aid of aqueous solutions of salts, the salts being added to heighten 

 the boiling-point) ; 3. Superheated steam ; 4. Chemical solvents. The 

 great bulk of all the sulphur produced is extracted by apparatus be- 

 longing to the first class, and including the calcarelle, calcarone, and 

 doppione. 



