300 Dr. G. Gore on the Molecular 



and did not prevent the maximum amount of chemical 

 change taking place. 



Experiment 12. — A mixture, each constituent solution of 

 which contained 1 grain of the substance in 1550 grains of 

 water was heated to 50° C. during two minutes, the liquid 

 cooled, and its energy measured ; it was 



Between 33,917 and 37,804 at 12° C. Average 35,860. 



The temperature therefore was hardly sufficiently high to 

 entirely change the mixture into the fixed product during 

 the given period of time. 



The circumstance that, by using either stronger solutions, 

 or heated ones, of the constituents of the mixture " A," the 

 latter yields the same amount of voltaic energy as that given 

 by the final product of the mixture " B," agrees with the 

 conclusion arrived at from therm ochemical data that "the 

 final division of the base between the two acids is the same 

 whether the soda were originally present as sulphate or 

 nitrate." 



Mixture " B." 



Experiment 13. — The solutions of sodium nitrate and sul- 

 phuric acid, of the degrees of strength of Nos. 1 and 3 

 (Exp. 5), were mixed, the mixtures heated to about 100° 0. 

 during two minutes, cooled, agitated, and their amounts of 

 energy measured. Each gave the same, viz. 



Between 30,511 and 33,917 at 14° C. Average 32,214. 



The mixture " B " therefore was evidently completely 

 formed and fixed in chemical constitution at the moment of 

 mixing, and whether the solutions of it were more or less 

 dilute, rise of temperature did not alter their amounts of 

 voltaic energy or their molecular constitution (see Table XV.). 



Experiment 14. — In this experiment, the two diluted acids 

 were first mixed, and heated to nearly 100° C; a dilute 

 solution of caustic soda, equivalent in amount to one of the 

 acids, and equally heated, was then added to them, and the 

 liquid cooled and agitated; it contained 1 grain of the sub- 

 stances in 1550 grains of water previous to dilution for 

 measurement of its energy. The latter then was 



Between 30,511 and 33,917 at 14° C. Average 32,214. 



Experiment 15. — The diluted constituent solutions of sodium 

 nitrate and sulphuric acid in the proportion of 1 grain of sub- 

 stance in 15,500 grains of water were also chilled to 3° C. 

 and mixed. The energy was then measured, it gave 



( Between 81,632 and 35,227 at 10° 0. Average 33,429. 



