Xt remain's, therefore, to ascertain what may be this new dfe- Facts and ob- 

 gree oi oxidation, produced by affinity, exclusively to give ex- tijramiJtsct.ni- 

 istence to a singular combinatioii, and to discover if it he ca- pou.ad*.' 

 pable of being exhibited separately, like those which we know 

 do form the maximum and minimum of tin. I shall conclude 

 this paragraph by observing tliat three operations, repeated 

 .with care, agreed to nearly half a grain in giving similar results. 

 The oxide at a maximum heated with sulphwr produced an 

 abundance of sulphureous gas, leaving mosaic gold as a residu- 

 um. In this- approximation, therefore, the metal abandoned 

 all the oxigen comprised between 28 per cent, and the new 

 term-, inferior at 22, which we have just discovered. 



If mosaic gold be- heated in a high temperature, the oxigeri' 

 .separates from the metal, combines with the sulphur, and es- 

 capes in sulphureous gas: but a part of the sulphur is retained 

 iirom the oxigen by' the metal itself: and the products are thus 

 metallic sulphufet, sulphuric gas, and sulphufet of tin. Such 

 atfi thfc new binary combinations produced by the ternary union 

 of mosaic gold, witen urged by a strong temperature. 



Bergmann, and after him Pelletier, were well convinced that 

 mosaic gold required for its formation a greater quantity of 

 ^ulphurthan the simple metallic sulphuret. For, besides the , 



sblphureous gas already mentioned, a portion escapes entire on 

 htea'ting the mosaic gold. It is a curious fact, that this metal, 

 whose affinity to sulphur might be expected to decrease in pro- 

 portion (o the quantity of oxigen it contains, should be capa- 

 ble of attracting a much larger portion than pure tin. 



If three parts of oxide at a maximum, and one part of mo'- 

 saic gold be made red-hot, the latter will be decomposed. The 

 sulphur contributes to disoxidate parts of the oxide ; sulphu- 

 reous gas is afforded, dnd after the operation a grey powder is 

 found, being a mixture of oxide at a minimum, metallic sul- 

 phuret, and white oxide. ]\Iuiiatic acid dissolves the gre}- 

 oxide, and the metallic sulphuret with this produces sulphu- 

 rated hydrogen. The oxide at a maximum, being much less 

 soluble, is the last to dissolve. After decanting and adding- 

 fresh acid, this second solution differs from the foregoing in 

 giving a yellow colour to hydro-sulpurated water, whilst' the 

 former gave a deep brown. 



Pelletier, who observed so acutely, has,sulifercd jiimself to 

 A'ol. XIV.— Mav, 1S0(), G bo 



