ANALYSIS OF NEUTRAL SALTS. 263 



analyses, my expectation was so disappointed, that T found 

 myself obliged to give up that principle; though, the more 

 I reflected on it, the more probable it appeared. During 

 my analyses of these metallic oxides I had observed auotlier 

 circuinstancethat caughtray attention, namely, that the quan- Ratios of ihe 

 tity of oxigen which saturated 100 parts of metal in the oxi- oxigen in dif- 



di •1.1K' [ jii I ferent oxidfs 



uie, was increased to halt as much more, or double as much „£ ^^^ ^^j^^^ 



in the oxide. Thus 100 parts o! lead with 7-8 of oxigen form metiii. 



the yellow oxldule, with 11*7 red oxide, and vvith ]5'6 brown 



oxide: 100 parts of copper with 1-2*5 of oxigen form the 



red oxidule, with 25 the black oxide : &c. 



I then proposed to determine the quantity of 'oxigen t;|j|.^jj. r._ 

 in sul[)huric and in sulphurous acid. To remove all lows the same 

 moisture from the sulphur, 1 combined it with lead. 1 ^"^'fS^' '" '^^ 

 found on this occasion, that lead absorbs precisely twice with metals,. 

 as much sulphur as oxigen at its minimut>i of oxidation; 

 and I soon ascertained, that it was the sanj^ with iron, cop- 

 per, and tin, I am since persuaded, that the native sul- 

 phuret of iron (the maximum) contain* for every hundred 

 parts of iron double the quantity of sulphur that exists in 

 the artificial (the minimum^ magnetic iron ore). From 

 these circumstances sulphur appears to me to follow the 

 same laws in its combination as oxigen. It follows too, that, 

 the composition of aa oxide being known, that of the sul- 

 phuret is easily found by a simple calculation, and the con- 

 trary. 



The sulphuret of lead, oxided by nitrorauriatic acid, -^j^g ^^j l^y^ 

 produced a neutral salt, without either the oxide of lead or in a sulphuret 

 sulphuric acid predominating. 100 parts of lead combined eJSuoirnfa'" 

 with 15*6 of sulphur yielded precisely the same quantity of suljih; 

 sulphate as 100 parts of lead dissolved in nitric acid, the solu- 

 tion being afterward mixed with sulphuric acid, evaporated to 

 dryness, and the residuum heated redhot. From these experi- 

 ments I was persuaded, that the sulphuret of lead contains 

 precisely the quantityof sulphur necessary for tHe formation 

 of the sulphuric acid required to saturate the oxide of lead 

 yielded by the same quantity of sulphuret. Experiments 

 on the sulphuret of iron at a minimum, and on the sulphate 

 of oxidule of iron, convinced me, that the same thing took 

 place with the sulphuret of iron. 



From 



ate. 



