108 Messrs. Johnson and Allen on the Equivalent 





Per cent, of 



Equiv. of Cs. 







CI. 



Cs. 



• 



1. 



21-044 ' 



78-956 



133-050 



Allen. 



2. 



21-031 



78-969 



133-150 



Johnson. 



3. 



21-043 



78-957 



] 33-054 



Johnson. 



4. 



21-063 



78-937 



132-892 



Allen. 



Average 21-045 78-955 133-036 



We may accordingly assume the round number (133) as the 

 equivalent of csesium. 



Calculated by this equivalent, the foraiula of bitartrate of 

 csesium corresponds well with the results of experiment. As 

 mentioned in the paper referred to, the analyses of this salt fur- 

 nished the following data : — 



I. 0*4718 grm. gave 0-0786 grm. water, and 0'294 grm. 

 carbonic acid. 



II. 0-5966 grm. gave 0*101 grm. water, and 0*372 grm. 

 carbonic acid. 



III. 1*3086 grm. gave 0*7708 grm. chloride of csesium. 



In two other estimations since made, 



IV. 2*0347 grms. gave 1*206 grm. chloride of csesium. 

 V. 1*8271 grm. gave 1*0857 grm. chloride of csesium. 



Calculated. Found. 



Cs= 123-35. Cs=133. }. II. III. IV. V. 



C 8 . 4800 1762 C 8 . 48 17*02 16-99 1702 



H6 . 500 1-83 H 5 . 5 177 1-85 1-88 



O 11 . 8800 3231 O" . 88 31-21 



CsO . 131-35 48-24 CsO . J141 5000 49-30 49-61 49-*73 



272 35 10000 282- 10000 



The equivalent number (133) brings csesium into a triad with 

 rubidium and potassium. "VVe have then two alkali triads, viz. 

 lithium (eq. 7), sodium (eq. 23), and potassium (eq. 39*1), 



and potassium, rubidium (eq. 85*36), and csesium, 



39 + 133 QA 

 —^- = 86. 



The correction of the equivalent of csesium implies a revision 

 of its spectrum, since the data given by Kirchhoff and Bunsen 

 with reference to both were obtained from the same impure 

 material. 



