636 
MESSRS. T. E. THORPE AND J. W. RODGER OX THE RELATIOXS 
Substitution of Halogen for Hydrogen. 
Bromine for hydrogen. 
Chlorine for hydrogen. 
n. 
Diff. 
+ jBr, 
Chloromethanes. 
7]dr. 
1 
Difference. ' 
Tjd^. 
1 
t 
1 
1 
2 
973 
310 
663 
Methylene chloride . . 
600 
147 
3 
1068 
294 
774 
Chloroform. 
747 
107 
4 (Iso) 
1171 
294 
877 
Carbon tetrachloride 
854 
On converting a monobromide into the corresponding dibromide, the viscosity rises 
by an amount which is approximately constant and equal to 300 units. If, however, 
the hydrogen atoms present in the same molecule be substituted in succession by 
chlorine, it is evident from the comparisons given that the effect diminishes as the 
number of chlorine atoms in the molecule increases. 
Compounds differing by a Carbon Atom. 
,ldl 
Difference. 
yd-. 
Difference. 
Tetrachlormethane 
Tetrachlorethylene . 
854 
1032 
178 
Methyl alcohol .... 
Aldehyde . 
358 
448 
90 
The different values given by the two comparisons may partly be due to tlie fact 
that the effect of the linkage of carbon atoms among themselves is different from 
that of a carbon atom to an oxygen atom, and partly to the effect of the molecular 
complexity of methyl alcohol. 
