50G 



Ki:rouT — 18h'4. 



wliicli of them we are to consider as most applicable to the case of the Volta 

 experiment. Perhaps one should take the most common or stable oxide; 

 pei'haps, seoinp^ that no combination is supposed actually to occur, aiul 

 since the metal is, so to speak, in excess, it is most reasonable to take 

 the lowest oxide which the substance will form. It may bo that the 

 (lata are not known for this ; it may even be that they have OTily 'oeeu 

 i)btained for the hydrate instead offer the oxide. 



I must therefore do the best I can, and quote several numbers 

 wherever there is obvious doubt. I imagine that J. Thomsen's are the 

 most reliable when they are availaT)le. 



But it must be remembered all through that since it is only tlio 

 itU'Jcncii to chemical action which is the cause of the Volta effect, whereas 

 combination heats are obtained by permitting or causing the combination 

 to actually occur, the numbers obtnined by calculation are not likely to be 

 quite right ; and they maybe expected to err on the side ofexcess, the cal- 

 culated number being higher than the actual value if directly observed. 



Enerijij of Comhinatinn of }[rf(tls with Oxygen. 



:Metal 



Zinc . 



Tin . 

 Lead . 



Iron . 



Nickel 

 Cobalt 



Copper 



Mercury . 



Silver 



'Hydrogen . 

 rotassiuQi . 



Mciloi'iile 



Zn.O 



Zn,0,HjO 



Sn,() 



Sn,0,H.,0 



i(«n,()..) 



SnO,d 



rb,0 



Fo,0 

 Fo,0,H.,0 



A(re,o;,) 



Ni,0,H.,O 



Co.O.lI^O 



Cu,0 



Ch.,0 

 CiiO 

 Hg,0 

 Hg..O 

 Ag,,0 



^'-'^';[ liquid 



f 



■ 2(K.H,()) 

 2(K,ll,(),Aq) 



K„0,Aq 

 . K,,0 



Aiitliciritv 



Thomsen . 

 Joulo 

 Andrews . 

 Favre and Sil- "1 

 bermaiin J 

 Thoniscn . 

 Andrews . 

 Thomson . 

 Andrews 



Tlioniscn 

 F. and S. 



Thomson 



i> 

 An<lrews 

 Thomson 



An<lrcws 

 F. and S. 

 Thomsen 

 .loule 

 Thomsen 



F. and S. . 

 Thomsen . 



»» 



Dulong, Hess, "j 

 Grassi,Jonle, |- 

 Kertlielot J 



Thomsen . 



Woods 



Heat (if 

 Fonini- 



tioii 



8.") 430 

 77000 



S-I8'_'j 



The i Mc.Li 



saino I'.xtreme: or 



re(hicc(l Value-* ['rol>.;ii!c' 

 to \'()lt.s ' \')il;;,! 



1-85 

 ICil 

 IvSt 



