r)U) 



r.moRT — 1884. 



i 



chloric acid also ; because, whatever effect the hj'drof^en affinity may have 

 itic'iaiigiiif^ the innnbers, it will have the same effect on all. 



It is easy to write down the hypothetical series in bromine and iodine in 

 the samo way — 



< 'iilriihi'''iJ Volla Seri'.-t in Bfomlne and Imliu}. 



. ^ _ ' 



I Mct.'il I III Hromino I In h<i\\\w I 



:!'S-) 



I -74 



1-tO 



I-IO 



•8t» 



•40 



:)r,o 



•ST 

 •f.o 

 •L':t 



-•K! 



All tiiis snpjtoses the metals to bo perfectly clean, and not covered with 

 a film of foreign s^-as like oxygen. On the hypothesis that the metal litis 

 been taken recently out of air. and that the film of oxygen with whicli it is 

 covered has to be torn from tlio jv.etal. though it was not actually com- 

 bined with it, the Volta series in chlorine or hydrochloi'ic acid would be 

 quite different, and more like this. 



Ili/pothefical VoUii Srri' 



f^ilvtT .... 

 liCiid 



It' A'r-C(if(fril ^^('lllls iti Chliruic or IICl. 







Iron 



11 



Unfortunately I can get no data for the heat of chlorination of nickel, 

 but assuming it not very ditl'ei'ent from iron, the above series gives copper 

 and nickel in the right order, as observed by Mr. Brown, whereas the other 

 one did not. I have no experiments with which to compare the numbers, 



Cdladate'l Vulfa Scries of Clrau MdaJx in Sulphur or Sulphureltcil 



llijiJriKjen. 



But it will be observed that this is nothing like the order to be ex- 

 pected in sulphuretted hydrogen ; for it is popularly known that copper 

 is more easily sulphurised in this gas than iron. Now assuming that the 

 metal had been covered with an air film, and that the oxygen of this has 

 to be replaced by sulphur, the chemical tendency, instead of being M,S, 

 is something more like M.S — ]\I,(), or possibly M,S — M,0 + H.j,0 — H.2,S; 

 atid either of these will give a quite different order. Data are given on 

 p. 624 of Naumann's ' Gmelin-Kraut,' vol. i., for the neutralisation heats 

 of various bases by H.jS, such as CuO + HjS, &c. These are something 

 like what wo want, and from them we reckon the following : — 



