SULPHUR IN VOLCANIC COUNTRIES. 333 



contains organic matter, or Bitumen, and is found coloured 

 black. When this Bitumen and Gypsum is exposed to volcanic 

 heat it is reduced to the condition of a Sulphuret of Calcium, 

 and when in this condition a small stream of heated water, or 

 steam, percolates through the mass of this material ; a second 

 decomposition ensues, in which sulphuretted hydrogen gas is 

 liberated. This gas coming in contact with any oxydising agent, 

 such as heated oxygen or steam, &c., deposits sulphur, and in 

 the lapse of time veins or masses of sulphur may thus be formed. 



No. 2 sample appears to show a less advanced condition of 

 the decomposition, in which the oxydation of the sulphuretted 

 hydrogen in sulphurous and sulphurio acid is slowly converting 

 the carbonate of lime into gypsum, and at the same time deposit- 

 ing sulphur; for when sulphuretted hydrogen is brought in 

 contact with damp limestone at a temperature about the boiling 

 point of water, gypsum and free sulphur are formed. 



From all that is at present known, it appears clear, contrary 

 to what was at one time supposed, that in the primary rocks 

 sulphur did not exist, because, if we believed in the earth having 

 been at one time in the state of igneous fusion ^ the sulphur could 

 not exist in a free condition, but must have united with the 

 metals. 



We conclude, therefore, that, like carbon, sulphur owes its 

 existence to the organic kingdom. Carbonic acid is decomposed 

 by living plants, and sulphates of the earth and alkalies are de- 

 composed by dead organic matter, and thus we once more notice 

 the important connection between the inorganic and organic 

 worlds. 



Febrtiaky 23, 1860. 



'Z s 



