86 



THE ATOMIC WEIGHTS. 



the CO2 was collected and weighed in an absorption apparatus, which 

 was tared by a similar apparatus after the method of Regnault. The 

 following percentages of CO2 in LijCOj were found : 



Mean of all, 59.674 



601 



645 



529 — rejected. 



655 

 683 

 604 



517 



663 



143 — rejected. 



794 



584 



Rejecting the two experiments which Dittmar regards as untrust- 

 worthy, the mean of the remaining nine becomes 59.638, ± .0173. This 

 combines with the work of Diehl and Troost, as follows : 



Diehl 59.417,4^.0060 



Troost 59-456, zt .0200 



Dittmar 59-638, =t .0173 



General mean , 59.442, ± .0054 



Dittmar's determinations give a much lower value for the atomic 

 weight, of lithium than any of the others, and therefore seem to be ques- 

 tionable. As, however, they carry little weight in the general combina- 

 tion, it is not necessary to speculate upon their possible sources of error. 



The ratios for lithium are now as follows : 



(i.) AgCl : LiCI : : 100 : 29.584, zb -0075 



(2.) Ag : LiCl : : 100 : 39.358, =b .001. 



(3.) LiCl : LiNOg : : 100 : 162.5953, ± .0025 



(4.) Per cent, of CO, in LijCOg, 59.442, zh .0054 



And the data to use in their reduction are — 



O = 15.879, ± .0003 N = 13-935, ± 0015 

 Ag = 107.108, =b .0031 C = 11.920, d= .0004 



CI = 35. 179, zh .0048 AgCl = 142. 2S7, =t .0037 



These factors give two values for the molecular weight of lithium 

 chloride, thus : 



From (i) LiCl = 42.0942, rb .oi 10 



From (2) " ^ 42. 1556, zb .0016 



General mean LiCl = 42. 1542, ± .0016 



