72 MODERN HIGH FARMING. 



Until about fifty years ago, the custom prevailed in Europe, 

 which largely prevails in this country, of manufacturing the acid 

 exclusively from sulphur; but in 1838, the king of Sicily was suffi- 

 ciently ill-advised to grant a monopoly of the Sicilian sulphur trade 

 to a commercial firm in Marseilles, France, and the consequence of 

 this, as of all other monopolies, was to create for the article an un- 

 fair and fictitious value. 



From twenty-five it was advanced to seventy dollars per ton, and 

 thus all large manufacturers were induced to seek for their raw ma- 

 terials in other directions. 



Some idea of the energy displayed in the endeavor to find this 

 required substitute, may be formed from the fact mentioned in one oi 

 Baron Liebig's letters, in which he says that during the short ex- 

 istence of the Sicilian monopoly, no less than one hundred and fifty 

 patents were taken out in Europe for the production of sulphuric 

 acid Irom gypsum (sulphate of lime) the whole of which were, prac- 

 tically speaking, industrial failures. 



That the substitute was eventually found, we are presently going 

 to see, and brimstone is now principally used in making gunpowder, 

 and for bleaching, and medical purposes ; although if, in price 

 and other advantages, it can ever vie with pyrites, there is no reason 

 why it should not again be the basis of the manufacturing process. 



PYRITES are sulphurets of antimony, arsenic, cobalt, nickel, cop- 

 per and iron, the two last being chiefly used for sulphuric acid 

 manufacture. They occur in immense deposits all over the world, 

 and mines are now in active work on a large and continually in- 

 creasing scale in the United States, England, Wales, Ireland, France, 

 Belgium, Germany, Norway, Sweden, Spain, Portugal and Canada. 



The annual quantity of pyrites consumed in the United States, 

 Great Britain, France and Germany combined, is estimated at 

 1 ; 750,000 tons, of which Great Britain alone takes over 850,000 

 tons, and the United States 175,000, the other two countries sharing 

 the balance in almost equal proportions. 



The following table of analyses will show the average composi- 

 tion of those ores, which have hitherto been found most suitable. 



