204 NON-METALS AND THEIR COMBINATIONS. 



16. SULPHUR. 

 S" = 32 (31.83). 



Occurrence in nature. Sulphur is found in the uncombined 

 state, mixed with earthy matter, in volcanic districts, the chief sup- 

 ply having been derived until lately from Sicily. Considerable 

 quantities are now also mined in the United States, chiefly in Louis- 

 iana, Utah, California, and Nevada. In combination sulphur is widely 

 diffused in the form of sulphates (gypsum, CaSO 4 .2H 2 O), and fre- 

 quently occurs as sulphides (iron pyrites, FeS 2 , galena, PbS, cinnabar, 

 HgS, etc.). Sulphur enters also into organic compounds, being a 

 normal constituent of all proteids, during the decomposition of which 

 sulphur is often evolved as hydrogen sulphide, which gas is also a 

 constituent of some waters. 



Properties. Sulphur is a, yellow, brittle, solid substance, having 

 neither taste nor odor. It is insoluble in water and nearly so in 

 alcohol ; soluble in benzene, benzin, ether, chloroform, carbon di- 

 sulphide, oil of turpentine, and fat oils. Sulphur is polymorphous ; 

 it crystallizes, from a solution in disnlphide of carbon, in octahedrons 

 with a rhombic base ; when, however, liquefied by heat it crystallizes 

 in six-sided prisms, and is obtained as a brown, amorphous plastic 

 substance by pouring melted sulphur into cold water. 



Sulphur melts at 115 C. (239 F.) to an amber-colored liquid, 

 which is fluid as water ; increasing the heat gradually, it becomes 

 brown and thick, and at about 200 C. (392 F.) it is so tenacious 

 that it scarcely flows ; when heated still further it again becomes 

 thin and liquid, and, finally, boils at a temperature of about 440 C. 

 (824 F.). 



In its chemical properties sulphur resembles oxygen, being like 

 this element generally bivalent, and supporting, when in the form 

 of vapor, the combustion of many substances, especially the metals. 

 Many compounds of oxygen and sulphur show an analogous compo- 

 sition, as, for instance, H 2 O and H 2 S, CO 2 and CS 2 , CuO and CuS. 

 While the valence of sulphur as a general rule is 2, in some com- 

 pounds it shows a valence of 4 or 6, as in SO 2 and SO 3 . 



Crude sulphur is obtained by heating the rock containing sul- 

 phur sufficiently high to cause the sulphur to melt, and thus to 

 separate from the earthy matters. As peculiar conditions (great depth 

 and quicksand) prevented successful working of the sulphur deposits 

 m Louisiana by the ordinary methods, sulphur is now mined there by 

 the following ingenious process : Superheated water, forced through 

 iron pipes to the deposits of sulphur, causes the latter to melt, and this 



