86 WRITINGS OF JAMES SMITHSON. 



grains of sulphate lead, which Mr. IIatchett obtained, cor- 

 respond to 48.08 grains of sulphuret of lead. 



I have found 10 grains of sulphuret of antimony to afford 

 11.0 grains of precipitate from muriatic acid by water. 

 Hence 31.5 grains of this precipitate are equal to 28.64 

 grains of sulphuret of antimony. 



The want of sulphuret of copper has prevented my de- 

 termining the relation between it and black oxide of copper, 

 but this omission is, it is evident, immaterial, as the quan- 

 tity of this sulphuret in the ore must be the complement of 

 the sum of the two others. 



But as the iron is a foreign adventitious substance in this 

 ore, it follows that the foregoing quantities are the products 

 of only 96.65 grains of it. 100 parts of the ore are there- 

 fore composed of 



Sulphuret of lead - - 49.7 



Sulphuret of antimony - - 29.6 



Sulphuret of copper - - 20.7 



100.0 



It is impossible not to be struck with the trifling altera- 

 tion which these quantities require to reduce them to very 

 simple proportions, or to think it a very great violation of 

 probability to suppose that experiments, effected with na 

 errors, would have given them thus : 



Sulphuret of lead - - - 60. 



Sulphuret of antimony - - 30. 



Sulphuret of copper - - - 20. 



However, I doubt the existence of triple, quadruple, &c. 

 compounds ; I believe, that all combination is binary ; that na 

 substance whatever has more than two proximate or true 

 elements ; and hence I should be inclined to consider the 

 present compound as a combination of galena and fahl- 

 ertz ; and if so, it will be accurately represented, as far as 



