SQQ OXIDATION^. 



caloric, and no tin is precipitated in the metalline Ttate. Tins 

 folution, vvhofe oxidation approaches the degree of minimum, 

 for the mofl part retains an aqueous tranfparency, without 

 any precipitation of oxide; even when long expofed to the 

 atmofpheric air, it does not lofe the property of changing the 

 yellow oxide of gold to a grey colour, or of dellroying the 

 blackidi brown tint of oxide of raanganel'e, when fixed upon 

 cotton. 

 Oxide of man* The oxide of manganefe is capable of various degrees of 

 ganefe. oxidation ; if a piece of cotton cloth be dipped in the tranf- 



parent folution of fulphate of raanganefe, it will, when dry, 

 retain its original whitenefs; but on their dipping the fame 

 "cloth in the liquor of carbonated or cauftic potafh, it will, 

 after wadiing and expofure to the atmofpheric air, be coloured 

 brown ; which colour will acquire a deeper fliade, ap- 

 proximating to black, on being fieeped for a time in an 

 oxigenated alkaline, muriatic liquor. The oxigenaled alka- 

 line liquor, on being for any length of time iubiuitted to the 

 action of the brown precipitate of manganeie, inftead of the 

 rag fieeped therein (which is to difTolve by means of an in- 

 creafed oxidation) will all'ume a purple colour, of greater or 

 lefs tranfparency as the time of their union has bfcn longer 

 or (horter. 

 Other oxides. There feems reafon, generally, to expe6l particular refults 



from fubmitting any of the metallic oxides to (he adion of 

 4hts oxigenated muriatic alkaline liquor; which might, per- 

 haps, be a means of giving them acid properties, and at the 

 fame time of proving the gradual oxidation of many metals; 

 this is the more obfervable in while oxide of lead, which be- 

 comes gradually coloured by long expofure to the oxigenated 

 liquor, and being frequently flirred. 

 Muriatic and Muriatic and nitro-muriatic folutions of tin, well diluted 



with water, have an aqueous tranfparency, when properly 

 made;, but if the two be mixed together, they acquire a fiuo 

 lefs in them- vinous colour, fimilar to that of Malaga ; this can only arile 

 lelves, acquire ^^^^ ^^^ oxigen of the nitro-muriatic being in part coin- 

 vinous t'lnc. nmnicated to the muriatic folution of tin. 

 The addition of ^^ ^ folution of gold with great excels of acid, and diluted 

 folution of gold with from 130 to 160 parts of water, be gradually poured 

 pie dvT- ^ ^^"^^ into the above mixture, flirring it all the time, the inlenlily 

 of the col.uur will be increafed, till at length the liquor be- 



njtro-muriatic 

 folutions of tin 

 though colour 



