G28 
MESSRS. T. E. THORPE AND J. W. RODGER ON THE RELATIONS 
increases with increase of molecular weight; the differences now vary within much 
narrower limits than at the boiling-point. 
Substitution of Halogen for Hydrogen. 
CjiH2KBro. 
Difi. 
ChlormetLanes. 
Diff. 
>1- 
V- 
'/• 
2 
455 
87 
368 
Methylene chloride . 
372 
16 
o 
O 
441 
69 
372 
Chloroform .... 
388 
-11 
4 Iso 
426 
66 
360 
Carbon tetrachloride . 
S77 
The conversion of a monobromide into a dibromide is accompanied by a marked 
rise in viscosity, which is less the higher the molecular weight. 
On the conversion of dichlormethane into the tri- and tetra-chlor compounds the 
change is very slight. As, however, the results for chloroform and carbon tetra¬ 
chloride aie extrapolated, the small difference may be due to errors thus introduced. 
Compounds differing by one Carbon Atom. 
>]■ 
Difference. 
Difference. 
Tetrachlormethane . 
Tetrachlorethylene . 
377 
446 
69 
Methyl alcohol . 
Aldehyde . 
i 
290 
316 
26 , 
The differences here obtained are now far removed from one another, no doubt for 
the reason given in the case of these comparisons at the boiling-point. 
Isom EES. 
Normal and Iso Compounds. 
Normal. 
Differeuce. 
Iso. 
'/• 
>1- 
Pentanes . 
299 
13 
286 
Hexanes. 
318 
6 
312 
Heptanes. 
330 
8 
322 
Propyl iodides. 
407 
17 
390 
Propyl bromides .... 
372 
19 
353 
Propyl chloTides 
330 
13 
317 
Butyric acids. 
379 
1 
378 
