3^4 EXPERIMENTS ON THE METALS FROM THE FIXED ALKALIS. 



Their method They say, that they heated potassium* in ammonia, and 

 of operation, tf, e y found, that a considerable quantity of ammonia was 

 absorbed, and hidrogen produced; and that the potassium 

 became converted into an olive coloured fusible substance. 

 By heating this substance strongly, they obtained three 

 fifths of the ammonia again, two fifths as ammonia, one 

 fifth as hidrogen and nitrogen ; by adding a little water to 

 the residuum, they procured the remaining two fifths, and 

 found in the vessel, in which the operation was carried on, 

 nothing but potash. — Again, it is stated, that, by treating 

 a new quantity of metal with the ammonia disengaged from 

 the fusible substance, they again obtained hidrogen, and an 

 absorption of the ammonia ; and by carrying on the opera- 

 tion, they affirm, that they can procure from a given quan- 

 tity of ammonia more than its volume of hidrogen. 

 and reas wing Whence, they ask, can the hidrogen proceed? — shall it 

 onit - be admitted, that it is from the ammonia? but this, say 



they, is impossible; for all the ammonia is reproduced. 

 It must then come from the water, which may be supposed 

 to be in the ammonia, or from the metal itself. But the 

 experiments of Mr. ikrthollet, jun., prove, that ammonia 

 does not contain any sensible quantity of water. There- 

 fore, say they, the hidrogen gas must be produced from 

 the metal; and as, when this gas is separated, the metal 

 is transformed into potash, the metal appears to be 

 i nothing more than a combination of hidrogen, and that 



alkali. 

 Defect in their It is obvious, that, even supposing the statement of these 

 ttatemeut. gentlemen correct, their conclusions may easily be contro- 

 verted. They affirm, that all the ammonia is reproduced ; 

 but they do not obtain it without the addition of zmter. 

 And of the oxigen which this would give to the potassium, 

 and of the hidrogen which it might furnish, to reproduce 

 the ammonia, they take no notice. 

 Mr. Davy's re- I have shown, by numerous experiments, many of which 

 suits veij dif- hayc been repeated before members of this Society, that the 

 results obtained, by applying heat to the fusible substance, 

 are very different from those stated by the ingenious French 



* Mem. d'Arcueil, Tom. II, p. 309. 



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