Constitution of Isomeric Solutions. 293 



It has already been shown by the voltaic-balance method, 

 that the action of chemical affinity between substances in 

 aqueous solution is not limited to small groups of a few dis- 

 similar kinds of molecules, such as those represented in 

 Tables III. to VIII., but extends to large aggregates com- 

 posed of a variety of molecules, the aggregates being appa- 

 rently without limit of magnitude or variety, but subject to 

 the law of chemical equivalence. The results given in Table 

 IX. further support this statement. The complex structure 

 in such cases is usually built up by making each addition 

 chemically equivalent to the whole of the previously existing 

 compound (see " A Method of Detecting dissolved Chemical 

 Compounds and their Combining Proportions," Roy. Soc. 

 Proc. vol. xlv. p. 265 ; also " The Loss of Voltaic Energy of 

 Electrolytes during Chemical Union," Proc. Birm. Phil. Soc. 

 vol. vi. part 2). 



Loss of Voltaic Energy during Mixing. 



In order to arrive at the loss of voltaic energy which took 

 place during the mixing of the two constituents in each of the 

 above cases, the average energy of each constituent was mul- 

 tiplied by its chemical equivalent, and the two amounts added 

 together to obtain the total amount of energy of the consti- 

 tuents. The average energy of the compound was then mul- 

 tiplied by its molecular weight, to arrive at its total voltaic 

 energy, and the product subtracted from the total voltaic 

 energy of its constituents. The following are the results: — 



Table X. 



Loss 

 Total loss. Per cent. 



2HN0 3 +H 2 S0 4 80,433,388 = 1023 



2NaN0 3 +Na 2 s °4 291,244 = 9149 



Na 2 S0 4 +2HN0 3 (Mixture"A") . 383,262,482 = 94*86 



2NaN0 3 ,H 2 S0 4 +Na 2 S0 4 ,2HN0 3 28,233,264 = 9562 



2NaN0 3 +H 2 S0 4 (Mixture < «B")... 373,550,432 = 97*70 



Na 2 S0 4 4-H 2 S0 4 375,154,338 = 97*81 



NaN0 3 +HN0 3 198,425,384 = 98'49 



In each of these instances the loss of voltaic energy appears 

 to be due to chemical union of the two dissolved substances. 



