SULPHUR AND PYRITE. 



BY JOSEPH STRUTHERS. 



[Joseph Struthers, mineralogist; born at New York City in 1865, and attended the 

 School of Mines, Columbia college (now Columbia university), graduating in the 

 course of chemistry in 1885; for fifteen years after his graduation he was on the staff 

 of instructors of the department of metallurgy at Columbia university; organized and 

 conducted the first summer school in practical metallurgy of Cohunbia university 

 (1896), which was at Butte, Mont. Dr. Struthers has visited many metallurgical 

 plants in the United States and Europe, and he has carried on special metallurgical 

 investigations; he has written numerous articles for the Engineering and Mining 

 Journal, Mineral Resources of the United States, Twelfth Census of the United States 

 and School of Mines Quarterly, and is the assistant editor of the Transactions of the 

 American Institute of Mining Engineers; appointed Field Assistant to the United 

 States Geological Survey for 1901 and 1902, and in May, 1903, special agent for the 

 United States census.] 



Sulphur has been known to mankind from the earhest 

 records of history. It is one of the most important elements 

 that comprise the earth's crust, and occurs in a free or uncom- 

 bined state in many countries, forming the mineral sulphur, 

 more commonly known in commerce as brimstone. 



The element is insoluble in water and nearly so in alcohol 

 and ether, but is quite soluble in carbon disulphide, petro- 

 leum and benzine. It burns in air with a blue flame, and is 

 oxidized into sulphur dioxide or sulphurous acid. It exists 

 in two distinct crystalline forms, and also as an amorphous 

 variety. These modifications are characterized by differences 

 in specific gravity, in solubility in various liquors, and in many 

 other respects. 



Sulphur is a pale yellow, brittle, crystaUine solid, with a 

 resinous luster, is almost tasteless, and emits a peculiar charac- 

 teristic odor when rubbed or warmed. It is a nonconductor 

 of electricity and an extremely bad conductor of heat. When 

 very gently warmed, even by being grasped in the hand, it may 

 be heard to crack by the mere warmth, and will ultimately 

 fall to pieces. At a temperature of 114.5° C. it melts into a 

 clear amber colored and moderately mobile liquid; on raising 

 the temperature of this Hquid, its color rapidly darkens, and 

 at the same time it loses its mobility until at a temperature 

 of about 230° C. the mass appears almost black, and is so vis- 

 cous that it can no longer be poured from the vessel. As 



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