('^74 MESSRS. T. E. THORPE AHD J. W. RODGER OH THE RELATIOXS 
'J'lns value is almost the same as the value of chlorine in ethylidene chloride, 
viz., 76. 
It is })robable, therefore, that in substituting hydrogen by chlorine in ethylene, the 
same or similar variations take place, as in the case of ethane ; for on producing 
CH3.CHCI3 and CClaiCClo, 
the first and second hydrogen atoms attached to a given carbon atom have alone been 
substituted, and the above numbers show that the mean value of the chlorine is about 
the same in both cases. 
The following table contains the values of chlorine calculated from the molecular 
viscosity work of the chlorine compounds examined ;— 
H = atoms of hy¬ 
drogen substituted in 
each methyl group. 
Chlormethanes. 
Chloretlianes. 
Chlorethylene. 
1 
*(H.CH„C1) 
89 
CHoCl.CHoCl 
83 
2 
H.CHCl, 
83 
CH.^.CHC1.. 
76 
CCh:CCb 
74 
3 
H.CCI 3 
71 
4 
Cl.CCh 
64 
It will be seen in conformity with the conclusions already stated that as N 
increases the value of chlorine always diminishes. It is also noticeable that when N 
is the same, the value of chlorine varies slightly with the series to which the 
substance belongs. This is again evidence of the fact already mentioned that on 
substituting hydrogen in a methyl group, the effect also depends upon the nature of 
the radicle to which the methyl group is attached. 
On comparing the differences between the specific molecular volumes of compounds 
belonging to the above series a similar v^ariation is noticeable, as is seen in the 
following table :— 
Chlormethane.s. 
Chloretlianes. 
Chlorethylene. 
N. 
Specific 
Specific 
molecular 
Difference. 
Difference. 
molecular 
Difference. 
volume. 
volume. 
1 
H.CHoCl 
50-8 
R.CH..C1 
CHCl: CHCl. 
79-6 
14-9 
16-9 
(17-5) 
2 
H.CHCl., 
65-7 
R.CHCl, 
CClo : CCE 
114-6 
18-8 
. 19-2 
3 
H.CCI 3 
84-5 
R.CCI 3 
* Tlie y.alne of chlorine here u.'sed is that "iven by tlie monohalogen componnd.s examined, 
