370 ^N METALLIC PIIOSPHURETS* 



Precipitates of § 4. The precipitates produced by phosphuretted alcohol 

 tin, lead, bis- in soluHous of tin, lead, bismuth, antimony, and platina, 

 m«ny', and ^^ ^ot differ from those obtained by means of alkalis, and 

 platina, by (^ some cvett bj alcohol ; except that the former are mixed 

 akoboL ^'^^^ ^ little phosphorus, the separation of which hastens 



that of the oxide. The phosphorus is simply mixed with 

 them however, for the colour of the precipitate is not alter- 

 ed by it; bat we shall see presently, that this is greatly 

 changed, as soon as a chemical combination of it with the 

 oxide takes place. 

 Very different To effect this I boiled two parts of phosphorus with one 



when the of caustic potash in about SIX parts of rectified alcohoI, the 



phosphurerteu ^ ^ m 



alcohol con- whole being contained in a small glass phiai *. The greater 



tains an alkah. p^j.^. ^f ^j^g phosphorus was not attacked, and could be used 



in the subsequent experiments. After cooling, the liquid 



let fali an oxide of phosphorus of a very fine red colour, 



and the supernatant fluid became perfectly clear. It was 



this that was employed in the following experiments. 



Nitrate of lead A portion of this phosphuret of potash in alcohol, being 



iprecipitated by poured into a solution of crystals of nitrate of lead in 

 this compo una. ^ . . , 



water, precipitated a substance of a fine orange colour. 



Commotions took place throughout the whole of the liquid, 

 and in a few moments black, shining, crystalline grains se- 

 parated ; which on examination comported themselves as 

 metallic lead retaining a little phosphorus. The same soln- 

 tion of nitrate of lead, one portion of which I treated with 

 spirit of Vi^ine impregnated with phosphorus simply, and 

 another with caustic alkali, yielded in each case a white pre- 

 cipitate; while alcohol impregnated with phosphuret of 

 potash immediately produced with it a very bright orange. 

 I then attempted to give this fine colour to the white oxide 

 thrown down by the alkali, by adding to it when separated 

 phosphuretted spirit of wine, bnt in vain : which proves, 

 that the orange-coloured substance is formed only at the 

 moment when the phosphorus and oxide meet in a state of 

 extreme tenuity favourable to their intimate nnion. 



Properties of § 5. This orange precipitate easily loses its colour, some- 



tbe precipitate. 



* An examination of the gas evolved in this process will be found 

 toward the end of this paper, at § II. 



times 



