SPECIFIC GRAVITY AND DISPLACEMENT OF SOME SALINE SOLUTIONS. 215 



column and between those in the same line in sub-table (c) are the same as those 

 between the molecular weights of the corresponding salts of the ennead MR to be found 

 in sub-table (c) of Table III., and what was said in this respect about the linear, 

 columnar, and diagonal relations of the molecular weights of the salts of the ennead 

 MR applies equally in the case of the ennead MRO3. The concentration, m, of the 

 mother-liquor, given in sub-table (e) is derived from its specific gravity. 



5 133. In sub-table {g) we have the values of D, the specific gravity of the salt in 

 crystal at T, referred to that of distilled water at the same temperature as unity. 

 If we examine the values of D, we see that they rise triadwise and parallel to the 

 values of the molecular weight. In order to study their differences the accompanying 

 table has been constructed : — 



Table giving the Specific Gravities, D, of the Salts of tJie 

 Ennead MRO^, and their Differences. 





K. 



Diff. 



Eb. 



Diff. 



Cs. 



C103 . 



2-319 



0-857 



3-176 



0-406 



3-582 



Diff. . 



0-900 





0-505 





0-527 



BrOg . 



3-219 



0462 



3-681 



0-428 



4-109 



Diff. . 



0-705 





0-655 





0-740 



IO3 . . 



3-924 



0-412 



4-336 



0-513 



4-849 



In this table we have the nine entries of the specific gravity of the crystals, and 

 these furnish six entries of independent differences taken column-wise, and an equal 

 number taken line-wise. The differences occurring in the lines correspond to pairs 

 of salts having the same acid and different bases ; those occurring in the columns 

 correspond to pairs of salts having the same base but different acids. In the upper 

 left-hand corner we have in the top line 0-857, which is the excess of the specific 

 gravity of RbClOg over that of KCIO3, and 0"406, which is the excess of the specific 

 gravity of CsClOg over that of RbClOg ; so that 0*857 is the increase of the specific 

 gravity of the salt MCIO3 when the substitution of Rb for K as the value of M is 

 efiFected. Similarly, the increase of specific gravity caused when the substitution of Cs 

 for Rb in MCIO3 is effected, is 0-406. 



Replacing CI by Br as R in KRO3 produces a rise of 0"900 in the specific gravity, 

 while the replacement of K by Rb as M in MCIO3 produces a rise of 857. When 

 Rb is replaced by Cs as M in MCIO3 and MBrOg the effects are similar, namely, a rise 

 of 0-406 and 0*428 respectively. The replacement of Br by I as R in KRO3 and 

 CsROg causes a rise of 0-705 and 0-740 respectively, while the replacement of Rb by 

 Cs as M in MCIO3 is very close to that produced by the replacement of K by Rb as 

 M in MIO3, namely, 0-406 and 0-412 respectively. These examples illustrate the 

 similarity of the substitution effect produced by elements having nearly identical 

 atomic weights but antagonistic chemical and physical properties. 



