BETWEEN THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 651 
Observed. 
Calculated. 
Difference 
per cent. 
Carbon tetrachloride .... 
1627 
2036 
- 25-1 
Carbon dichloride. 
1933 
2188 
- 13-2 
Ethylidene cliloride .... 
1336 
1402 
- 4'9 
Water. 
398 
492 
- 23-6 
The behaviour of these substances is substantially what it was at the smaller slope, 
where the differences between the observed and calculated numbers were respectively 
- 23-5, — 9-9, — 37, and — 23-8. 
The identical values given for the differences in the case of water are especially 
noteworthy, as the molecular complexity of water is supposed to alter as the tempe¬ 
rature falls. 
It has already been shown that the molecular viscosities of the acids—which, like 
water, are also supposed to contain molecular aggregates—are related to those of the 
other liquids in practically the same way at the two slopes. These points are of the 
highest importance in justifying the use of temperatures of equal slope as tempera¬ 
tures of comparison. For although the temperatures of slope, and thus the 
molecular viscosity corresponding with these temperatures, will be affected by the 
existence of molecular aggregates, yet the above facts indicate that the relationships 
obtained at any one value of the slope are general, and will be the same, no matter 
at what slope the comparisons are made. 
Bromine and the Alcohols. 
The comparison of the observed values for bromine and the alcohols with those 
calculated from the preceding fundamental constants, which were entirely deduced 
from the molecular viscosities of the other liquids, is given in the table. 
Observed. 
CalcLilated. 
Difference 
per ceiii. 
Bromine. 
1317 
1392 
- 5-7 
Methyl alcohol. 
760 
720 
5-3 
Ethyl alcohol. 
933 
951 
- 1-9 
Propyl alcohol ...... 
1041 
1182 
- 13-5 
Butyl alcohol. 
1232 
1413 
- 14-7 
Isopropyl alcohol. 
930 
1142 
- 22-8 
Isobutyl alcohol. 
1137 
1373 
- 20-8 
Inactive amyl alcohol . 
1386 
1604 
- 15-8 
Active amyl alcohol .... 
1334 
1604 
- 20-2 
Trimethyl carbinol. 
1020 
1333 
- 30-7 
Dimethyl ethyl cai’binol . 
1190 
1564 
- 31-4 
Allyl alcohol. 
1047 
1105 
- 5-5 
4 O 2 
