the Concentration of Hydrogen Ions in Solution. 339 



N 

 To test the method, experiments were made with an — HC1 



solution. Four experiments gave 295, 2*75, 2 - 95 and 2'95 c.c. 

 of carbon dioxide respectively. Taking the mean we get for 

 the concentration of hydrogen ions x — 049. The value obtained 

 from Krannhals' measurements of the conductivity at 100° C. is 

 x = "0475. The two methods therefore give concordant results. 



Strength of 

 H 2 S0 4 used 



Volume of C0 2 

 from "1 gm. 



ax = — -1 



C 2 



x from con- 

 ductivity 



a 



N 



To 



2-42 c.c. 



343 



•06 



52 



N 

 15 



3-17 „ 



2-15 



•043 



50 



N 

 20 



3-87 „ 



1-58 



•0335 



47 



N 

 30 



4-88 „ 



1-05 



•023 



46 



N 

 60 



5-05 „ 



•68 



•013 



52 



N 

 120 



6-85 „ 



•46 



•007 



65 



N 



OO 



8-5 „ 



■18 







00 



The authors are making similar experiments with other deriva- 

 tives of oxalacetic acid and are also investigating the velocity of 

 the reaction. In conclusion they wish to thank Mr Fenton for his 

 kindness in allowing them to proceed with this work, and Pro- 

 fessors Liveing and Dewar for kindly placing the resources of 

 their laboratories at their disposal. 



VOL. XI. pt. V. 



25 



