Messrs Fenton & Jones, On a method of comparing, etc. 109 



Based upon these changes a very simple method has been 

 devised for comparing the affinity-values of acids, and the results 

 agree remarkably well with those obtained by the well-known 

 methods. 



In order to explain the nature of the changes involved, the 

 authors attribute the evolution of carbon dioxide to the instability 

 of the negative ion, and they have now made further experiments 

 in order to test this hypothesis, the results being in all cases 

 favourable. It is further shewn that it is possible by this method 

 to compare the ionizing capabilities of various solvents, and 

 experiments have now been made with pyridine in order to throw 

 light upon the disputed question of its behaviour in this respect. 



Von Laszczynski and von Gorski have found that inorganic 

 salts have marked electric conductivity in pyridine solution, 

 whereas Werner on the other hand found normal molecular 

 weights from such solutions. 



Examined by the present method the following result was 

 arrived at : 



01006 gram hydrazone dissolved in 7'5 c.c. of dry pyridine 

 gave 6"12 c.c. of carbon dioxide (corr.). 



Under exactly similar conditions the following results were 

 obtained with other solvents : 



Wt. of hydrazone Vol. of C0 2 



Water 0-0975 7-96 



Amyl alcohol 0"0989 3-56 



Toluene 0-1078 2'29 



Nitrobenzene 01026 2-29 



It will be seen therefore that, on the hypothesis mentioned 

 above, pyridine exerts a very considerable ionizing function. 



On isomeric esters of dioxymaleic acid. By H. J. H. Fenton, 

 M.A., and J. H. Ryffel, B.A., Peterhouse. 



\Read 18 February 1901.] 



It was shewn by one of the authors on a previous occasion that 

 the ethyl ester of dioxymaleic acid exhibits the remarkable pro- 

 perty of becoming liquid when kept in a desiccator in presence of 

 air, although it is relatively stable in presence of moisture or in 

 absence of oxygen. This property has now been further investi- 

 gated, and it is shewn that oxidation and loss of water take place 

 with the formation of the liquid ester of dioxytartaric acid which 



VOL. XI. PT. II. 9 



