Constitution of Isomeric Solutions. 297 



energetic chemical action occurring at the moments of mixing 

 of those solutions than during the mixing of the weaker ones. 



Mixture " B." 



Experiment 5. — Four solutions, of different degrees of 

 strength, were also made of the isomeric mixture of 2 mole- 

 cular weight proportions of sodium nitrate and J of sul- 

 phuric acid, exactly in the same manner as those of "A." 



Table XIV.— 2NaN0 3 + H 2 S0 4 . 



No. 1 contained 1 grain of the mixture in 15*5 grains of water. 



„ 2 „ 1 „ „ 1550 



„ 3 1 „ „ 1,550-0 



„ 4 1 „ „ 15,5000 



The amounts of voltaic energy given by these, after suitable 

 dilution, were : — 



Table XV. 



No. 1. Between 30,511 and 33,917 at 15° C. Average 32,214. 

 „ 3. „ 31,000 „ 34,444 „ 18 „ 32,722. 



„ 4. „ 30,511 „ 33,917 „ 12-5 „ 32,214. 



That of No. 2 was not measured. The results show that 

 the mixture of sodium nitrate and sulphuric acid was much 

 more stable than that of sodium sulphate and nitric acid ; and 

 that variation of degree of dilution did not change the amount 

 of its voltaic energy, and probably also not the distribution of 

 acids and base in it. 



According to the statements, that " two thirds of the soda 

 combines with the nitric acid and one third with the sulphuric 

 acid," and that "the final division of the base between the 

 two acids is the same whether the soda were originally present 

 as sulphate or nitrate," considerable chemical change must 

 have occurred during the mixing of the ingredients of " B " 

 (as well as during that of "A"). And as the amount of 

 voltaic energy of completely decomposed "A" is the same as 

 that obtained at the outset with " B " (see Tables I. and XV.), 

 the latter mixture attains completely its final state during the 

 process of mixing. The thermal phenomena also support this 

 conclusion. 



In J. Thomsen's experiments with each of the mixtures 

 "A" and " B," " the quantity of water serving as solvent varied 

 but slightly, so that the results of the experiments only hold 

 good for dilute solutions " (' Theories of Chemistry,' p. 467). 



Influence of Order of Mixing. 

 Experiment (3. — In each of the previous experiments a solu- 

 tion of the salt of sodium was first taken, and then one of the 



