ON POTASSIUM AND SODIUM. \ Jl 



" number of properties must always be the foundatidn of 

 " arrnnj^ement." Now I think Mr. Dalton will not deny 

 this position ; I would tlierel'ore iisk him, whether the num- 

 ber of analogous properties is <;reutest between potassium 

 and sodium, nnd the j^aseous compouuds of hidrogen, 

 which he has enumerated, or between the yiew and the 

 common metals. If the new m^Hals be hydrurets, it follows, 

 I tliink indisputably, that the common metals must be 

 hydrurets; also and for that matter, the reasoning derived 

 from their specific gravities makes as much against as for 

 the argument, or rather it is decidedly adverse to it. 



I have already exceeded the limits, to which I intended Mr. Dalton's 

 to have confined my remarks on this part of Mr. l^alton's ^^^^^^^'^^^|'^'^^^^^^^ 

 new system; I shall therefore but briefly notice his observa- potassium in 

 tions on the combustion of poiassium in muriatic acid. Jt n^"''*^'*^^^**^* 

 is very singular, as he says, that the French chemitts, and 

 Mr. Davy, should have adopted the same explanation to 

 account for the hidrogen produced, their views of the ha- \ 



tnre of potassium being so difl:erent. That, at the time he 

 made the experiment, Mr. Davy should have concluded, 

 that water contained in the gas was the source of the hidro- 

 gen, was perfectly natural; but, if Mr. Dalton be correct, 

 water cannot exist, either in this gas, or in fiuoric ucid gas, 

 (vide new System, pjJge 282) and consequently Mr. Davy's 

 conclusion must have been wrong; but Mr. Dalton's, and 

 that of Gay-Lnssac and Thenard, that it came from the 

 potassium, are not niore correct, for the late admirable 

 " Researches on the oxi muriatic acid'* &c., as detailed in 

 Mr. Davy's lust paper, Phil. Trans. 1810, page 231 *, Mr Davy's cx- 

 prove, that the true origin of the hidrogen was from t'l^e ^'^'^"^''"^^ **^ '** 

 muriatic acid itselt, independent of water. This acid be- 

 ing composed of the peculiar siu)ple body, oximuriatic acid 

 (! mtjht call it by its old improper name, for want of a 

 better], with a base of hidrogen ; by the combustion of pot- 

 ussinm in which a compound of oximuiiatic acid and pot- 

 r-v^sium is formed, and the base evolved. 



Mr. t)alton, in his appendix, mentions Mr. Davy's paper "fhe expcri- 

 inst alluded to, but still retains h'.s opinion, that the hidro- ""^"^ v^o^e 



♦ J.^urnal, vol. XXVH, p S2J. 



jjerr- 



