32 



Mr. William Sutherland on the 



For the trihasic acid radical the ratio 3B/F is 12, and 

 therefore 2B/F is 8 ; for the tetra basic radical 4B/F is 17, 

 and therefore 2B/F is 8*5; and both these values for 2B/F 

 range themselves with the values found for 2B/F in the 

 dibasic radicals. This, then, is a noteworthy result, that for 

 all acid radicals of a basicity higher than 1 the ratio 2B/F is 

 nearly constant, and has half the value of the same ratio for 

 radicals of basicity 1 . This recalls the result we found before, 

 that for atoms in organic compounds the ratio B/F has a 

 value nearly half of that for the elements and CH 4 , C2H4, and 

 CH 2 . Our results for the acid radicals may be summed up 

 in the two formulas — B = 9F nearly in the unibasic, 2B = 9F 

 nearly in the poly basic. 



The last compounds to be considered briefly in the present 

 paper are the organometallic, for which ~M 2 l can be calculated 

 by the equation (14), 



M' 2 Z=1190xlO" 6 M Vl T 6 , 



with the data collected by Carnelley (Phil. Mag. 5th ser. xx. 

 p. 260), namely, the boiling-points and densities at about 

 15° C. of various methides, ethides, and so on. In the fol- 

 lowing table these data are not reproduced, but only the 

 values of M/p and (M 2 /)* calculated from them. The types of 

 compound are indicated by the headings ZnR 2 , SnR 4 , and so 

 on, R being CH 3 in the first row, and so on. 



T.able XXV. 





ZnR 2 . 



HgR a . 



SnR 4 . 



PbR 4 . 





(M. 2 l)i. M/p. 



(M 2 ^. M/p. 



(Wlf M/p. 



(M 2 lf M/p. 





... 5-1 68 



57 75 



75 136 



8-2 130 



C 2 H 5 ... 



... 69 104 



7-4 106 



103 197 



10-6 202 



C 3 H 7 ... 



... 84 137 



8-6 135 



120 263 



— — 





Br 3 . 



SiR t . 



NR 3 . 



PR 3 . 



CH 3 ... 











C 2 H 5 ... 



... 7-8 140 



97 187 



7-7 138 



83 146 



C 3 H 7 ... 



— — 



12-3 263 



— — 



— — 



C 4 H 9 ... 



... — — 



— — 



11 7 237 



— — 





AsR 3 . 



SbR 3 . 



OR 2 . 



SR 2 . 



CH 3 ... 



— — 



68 110 



— — 



5-2 74 



C 2 H 5 ... 



... 8-5 140 



90 158 



6 1 101 



6-8 107 



C 3 H 7 ... 



— — 



— — 



— — 



83 145 



C 4 H 9 ... 



... — — 



— — 



9-1 169 



97 174 





C1R. 



BrR. 



IR. 





CH 3 ... 



_. . 



4-3 57 



— — 







..4 8 69 



52 74 



5-7 80 





C 3 H 7 ... 



.. 5-7 87 



60 89 



66 97 





