116 Prof. W. Ostwald's Electrochemical Researches. 



pation in the electrolysis of the second hydrogen atom of 

 oxalic acid. The marked increase in the value of log tan m is 

 very characteristic. 



Sulphuric acid is stronger than oxalic acid ; the second 

 hydrogen atom of sulphuric acid will therefore probably 

 sooner take part in the electrolysis, the maximum of the mo- 

 nobasic acids will be overstepped, and another maximum will 

 be approached which we may suppose will be double as large 

 as that of the monobasic acids. The following numbers were 

 obtained : — 



Sulphuric Acid, H2SO4. 



p- 



v. 



m v 



m 2 . 



m. 



1 



2 



927 



92-7 



92-7 



2 



4 



96-4 



96-4 



96-4 



3 



8 



100-7 



100-5 



100-6 



4 



16 



1075 



107-2 



107-4 



5 



32 



116-3 



116-2 



116-3 



6 



64 



1270 



127-4 



127-2 



7 



128 



139-5 



138-9 



139-2 



8 



256 



1506 



150-6 



150 6 



9 



512 



1610 



160-8 



160-9 



10 



1024 



169-3 



168-9 



169-1 



11 



2048 



174-5 



174-3 



174-4 



12 



4096 



1771 



177-0 



177-1 



13 



8192 



1771 



176-6 



176-9 



14 



16384 



174-3 



174-1 



174-2 



Neither these numbers, nor those obtained by referring the 

 conductivities to the equivalent weight of sulphuric acid, can 

 be made to agree with the normal curve. The separate 

 actions of the two hydrogen atoms of sulphuric acid are 

 shown very markedly in the results recently obtained bv 

 F. Kohlrausch (Gott. Nadir. J 885, p. 80). The conducti- 

 vities of the stronger monobasic acids appear as straight lines 

 in the system of coordinates chosen by Kohlrausch ; the curve 

 of sulphuric acid forms two straight lines at different inclina- 

 tions, joined by a short curve which falls at the dilution 2-8 

 litres. The table given by the author contains therefore the 

 second part of the complete curve. As Kohlrausch did not 

 examine any other dibasic acid of nearly the same strength as 

 sulphuric, the behaviour of this acid remains unexplained by 

 his results. 



The point at which the second hydrogen atom of a very 

 strong dibasic acid begins to take part in the electrolysis is 

 situated in the concentrated solution. Dilute solutions of 

 such an acid behave similarly with the monobasic acids,, pro- 

 vided that molecule is not compared with molecule, but 



