438 Pressure in Electrical Conduction and Decomposition. 



electrical resistance and on the quantity of gas liberated from 

 dilute sulphuric acid, but what there is is slight. There seems 

 to be a small decrease in the resistance, but I cannot yet say 

 to what this is due ; for this part of the investigation is in- 

 complete, and it is exceedingly difficult to distinguish and 

 separate between possible causes. 



3, Ozone is present in the gases liberated by the bursting 

 of the electrolytic tube. 1 have not estimated it quantitatively, 

 but I have no reason to think it present in unusual amount. 

 Under some conditions, e. g. during the formation of ozone 

 under the influence of the silent discharge, pressure might 

 facilitate the condensation of oxygen to ozone. 



It may, finally, be needful to increase the pressures employed 

 in this investigation still more, and to employ vessels of steel 

 or of some other material. The whole investigation is one of 

 great difficulty, but I shall probably publish a fuller account 

 of the methods and results of which the above forms a short 

 and very imperfect summary*. 



Addenda to the Author's paper u On certain Cases of Electro- 

 lytic Decomposition" Phil. Mag, July 1885. 



Page 38, line 5 from top, omit binary. 



Page 38, add: — Dr. Gore has discovered that heated argentic 

 fluoride commences to conduct while still solid, and that when 

 fused its electrical resistance is very small. He appears to 

 regard the conduction in both cases as being unaccompanied 

 by decomposition, i. e. non- electrolytic. 



Page 4.3, line 15 from top, for (and Hg 4 I 6 ) read (and 

 H S T 6?). 



Page 39, line 6 from bottom, add : — It is of interest to 

 remark, in connection with the electrolytic decomposition of 

 glassat 100° C, that I have recently learnt from Mr. Hicks 

 that it may also be annealed at this temperature. 



Pages 40 and 45, add : — Amongst the properties of fused 



To^tlie proof I have an opportunity of adding that, since the above 

 was written, I have found a short paper by M. Bouvel in the Comptes 

 Rendus, t. lxxxvii. p. 1068, wherein he states that he has found experi- 

 mentally that : — 



(1) La decomposition de Teau par un courant est independent de la 

 pression. 



(2) La quantite de l'electricite necessaire pour decomposer un meme 

 poida d'eau est sensiblement la meme quelle que soit la pression a laquelle 

 s'opere la decomposition. 



M. Bouvel verified these statements up to 200, and found that the 

 decomposition was not stopped by a pressure of 360 atmospheres. 



