DIMINUTION OF DrXATABrLITJr CT SPIRIT THERMOMETEttS. ^5 



the ti'iie one, which in this case is in the state of peroxide;, 

 hut, in its common form (potash) it is only a protoxide, 



*' Fo-tasslum bxiiii« in fluoric ncid jjas, and the result is Flnoric acid 

 *' fluiite of potash and some h!droi»en. The UR^ory of thisis •><>* |a7compouJid" 

 " obvious.'* Accordini? to Mr. Dalton's views it is not ; but 

 is it too bold a conjecture to imaoine, tliat something sinai- 

 hir to wiv.it takes place, when poiasyiura is burnt in muri'- 

 atic acid ^as, occurs Ijere also? and that hi^Jrogei> is pro- 

 bably the base of fluoric acid i^ns, united perha|)s to some, 

 as yet unknown body, of the same class as oximuriatic gas? 



A,S'tJafiv6iinikrity between the properties of potassiwra The same ar. 

 ?hk1 sodium is so great, I omit saying* any thing on the ^'i*^- f^I'^,du!afas4o 

 tcr, more than the remark already made, res [)*ictiug the poiassmm, 

 diK'ercnce in the results with potash and soda in the gun- 

 barrel experiment. The arguments for the undecompound- 

 ed natiu(! of potassiun^ are equally applicable to that of 

 M)di(im. 



From a candid review of all the facts, I think It must be Mr palton*5 

 nUoM(*?«l> that Mr. Dalton does not make out his case; and sp^"iuTP them 

 that potusHiium and sodium ronsequentiy stand in the class, therefore not 

 where thtir illustrious diacoverer has placed them, it will J"^*^^^ 

 be observed, that aluicst all the arguments, which I have 

 broa;j;ht forward in opposition to Mr. Dalton's idea of the 

 compound nature of the new metals, are derived from Mr. 

 Davy's papers: and it is not sinall praise, that he has sent 

 his laboursi so perfect into the world (new? and difficult as 

 th^y htiv« !>«**«), that his own couclusioHa, fouiwled oa Jjxid 

 supported by his own expevimentSy form the ablest and 

 most perltct defence against all the attempts, that have 



been made to overthrow them. i :>':?••?». 



JUSTUS. 



XI, 



imt: ih. 



Observations on the Diminution of T)ilatability of Spirit if 

 Wine TUermometcrs ; by HpNoajC; It^Ay,6E^,GyES*. . 



ALLEY and Muschembfoeck have asserted, tliiat ^pi- Spirit tliermo* 

 rit Qi'wiii« employed for thermometers in course^of time""^^^'^'^ ''^^ 



- ^ ' ♦ /ournal <le Physique, Tul. LX VI, p.^Oa^. >^ 



loses 



