M. J. Thomsen's Thermo -chemical Researches, 



419 



phate of soda. We then obtain 



u = /3=l, 7 = S = 0; 

 so that the value of x is simply 



n 



x = 



n+\ 



Now, experiment having shown that in this case x — ^, it follows 

 that n=2. 



Thus, for all the reactions which take place between sulphuric 

 acid, nitric acid, and their salts of soda, we shall have 



M. Thomsen has calculated, by means of this formula, the mag- 

 nitude of the decomposition in all the experiments in which he 

 caused nitric acid to act in various proportions on combinations 

 equally varied of soda and sulphuric acid, and afterwards the 

 thermic effects corresponding to the decompositions indicated 

 by this theory. 



The following Table recapitulates all these results, as well as 

 those which relate to the action of hydrochloric acid, and which 

 have been calculated by the same formula. In it are shown : — 

 the value of x — that is to say, the proportion according to which 

 the chemical decomposition must take place according to the 

 theory of Guldberg ; the thermic effect calculated from that de- 

 composition ; and the thermic effect found by experiment : — 









Thermic effect. 



Reagents. 





x . 

















Calculated. 



Found. 









thermal units. 



thermal units. 



NaO,S0 3 



.|HO,N0 5 



0121 



- 462 



- 452 





4 



•T » 



•2 



0-232 

 0-423 

 0-667 



- 828 

 -1331 

 -1773 



- 808 

 -1292 

 -1752 



" 







• 1 



0-845 



-1974 



-2026 





•3 „ 



.2 HO, NO 5 



0-903 

 0-845 



-2019 

 -1974 



-2050 

 -2026 



NaO, SO 3 



NaO,2S0 3 





0-742 



- 982 



- 978 



NaO,3S0 3 



0-667 



_ 714 



- 664 



NaO,4S0 3 





0-607 



- 551 



- 520 



\ NaO, SO 3 -K NaO, NO 5 



£HO,N0 5 



0-167 



- 561 



- 546 





* 



0-271 



- 786 



- 761 





1 



0-371 



- 933 



- 968 



NaO.NO 5 



.1HO, SO 3 



0-333 



4- 298 



-f- 288 





..2 



0-458 



+ 348 



+ 379 



NaO,S0 3 



..£HC1 



0-423 



-1279 



-1247 





-.1 „ 



0667 



-1691 



-1682 



1 „ 



..2 „ 



0-845 



-1870 



-1878 







..4 



0921 



-1917 



-1896 



!NaCl 



..1HO, SO 3 



0-333 



+ 257 



4- 244 







1 



..2 



0-458 



4- 292 



4- 336 



2E2 



