262 K. IKEDA 



Then by the formula we have 



x(m'a + n'b-\-p'c+ ) Tr I m'a±n'b+p'c + 



hp = A = — ■ f^ . Hence x = 



(m'a-\-n'b+))'c J r } 2 



KW , 3 



For example, toluene contains 91.3 % °f carbon and 8.7 °/ of 

 hydrogen ; dividing the one by 11.97, and the other by unity, we get 

 the empirical formula C 7m6S H ejl =M— 100. The specific gravity at the 

 boiling point is 0.776, so that V -128.8 and the observed value of K 

 is 3.692. Substituting these values in the above formula we have 



(7.68x600 + 8.7x75); ftQn 



V- = : = .aOi). 



(3.692) 2 x(128.8) 3 



Therefore, the molecular magnitude is C 7 . G3x . 939 / / s - . „ :;r , r =C 7 _ u H &M . 

 This result is too high by 2 °/ , inasmuch as the calculated and the 

 observed values of A.' show a difference of 1.1 %• If this difference 

 be 2 % as it i 8 most likely to be, then the molecular magnitude would 

 differ by 1 °/ , which may be regarded as fairly approximate. But 

 whenever this mode of determining molecular magnitude is applicable, 

 the vapor density method can also be employed, so that this applica- 

 tion of capillary determination is more curious than useful. 



The second formula seems to be of greater interest to chemists, 

 for it shows the close relationship between the mode of atomic linking 

 and the capillary phenomena. It can be applied with caution to 

 determine the number of double bonds in carbon compounds, for 

 whenever there is one the value ofl K 1,18 is increased by about 19 



units, which is quite a large quantity compared with the probable 



i 

 discrepancy between the observed and the calculated values of K V 118 . 



Benzene has three double bonds according to this mode of calculation, 



while ally 1 compounds seem to have only one such bond. This is in 



accordance with the conclusion of Brühl from optical determination. 



