Volumes of Salt-Solutions. 



185 



the A is independent entirely of the quantity of water of 

 crystallization in the salts, the utmost variety existing in 

 this respect failing to make itself evident in the molecular 

 volumes. 



Table IV. gives the change in molecular volume produced 

 by the substitution of chlorine for the group (N0 3 ), and for 



bromine also the difference M/ NO3 ~ J. 



Table IV. 



No. in 

 Table II. 



M. 



n. 



rc(MN0 3 ). 



«(MC1). 



Diff. 



A Diff. 

 n 



Aq. 



2-51. 



K 



2 



1879-6 



1857-1 



22-5 



11-3 



0-0 



16-52. 



Na 



2 



1858-6 



1836-3 



22-3 



11-2 



0-0 



44-37. 



Ba 



2 



2 



3650-4 



3626-5 



23-9 



11-9 



0-2 



45-38. 



Sr 

 2 



2 



36439 



3621-7 



22-2 



111 



0-6 



9- 1. 



K 



1 



w(MBr). 



w(MCl). 





74 



0-0 



1835-1 



1827-7 



23-15. 



Na 



1 



1824-8 



1817-5 





73 



2-0 



2-11. 



K 



2 



m(MN0 3 ). 



PO 



61-2 



30-6 



0-11 



1879-6 



3618-4 



16-25. 



Na 



2 



1858-6 



3597-6 



610 



30-5 



0-10 



In all these cases the agreement is satisfactory, the only 



marked deviation being in '— (N0 3 — CI); but it must be 



remembered that Ba(N0 3 ) 2 is an exceedingly insoluble salt, 

 and the solution in the table is nearly saturated, while the 

 BaCl 2 solution is not nearly so. 



We come now to the important class of sulphates, of 

 which seven are included in Table II. ; and, as before, I have 



taken the difference Ml CI — 4 j. Table V., which contains 



the figures for the above is divided into two parts : the first 

 portion contains those sulphates which either crystallize with 



