Stubbs. — Conduclivitij of Aqueous Sohifioits of Carhon-dioxide . 19 

 The following is a table of results (temperature 18° C.) : — 



The values obtained for the conductivity at different pressures disprove 

 Pfeiffer's statement that conductivity does not vary with increase of 

 pressure. These values lie on a regular curve which ascends very sharply 

 from to 1 atmosphere, and thereafter much more gradually. The influence 

 of concentration on conductivity decreases fairly rapidly as the concen- 

 tration increases, but does not vanish even at the highest pressure. 



Series II. 



Temperature = 0° C. 



Work was begun with ascending pressure, and a complete range of 

 values obtained. Subsequent work was under very varying conditions of 

 temperature and pressure, such being called for by the observed phenomena. 



The following table gives the first results (temperature 0° C.) : — 



Pressure : 

 Atmospheres. 



Final 

 Bridge-reading. 



Resistance. 



Conductivity. 



So far the behaviour corresponded exactly to that at 18°, the conduc- 

 tivity being, of course, considerably lower. Wroblewski was said to have 

 discovered a hydrate formed at 0'^' under pressures given as 12-3 or 16 atmo- 

 spheres of CO,, and it was anticipated that if such a hydrate existed there 

 should be abnormal behaviour of the conductivity at these pressures ; but 

 such was not the case. 



The pressure was now let down, the intention being to work with de- 

 ,scending pressures over the same ground. For all future work the resistance 

 used in the box was 500 ohms. 



