BETWEEN" THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 683 
Isomeric Alcohols .—The following table contains the observed values for the 
different groups of isomeric alcohols :— 
Propyl alcohol. 
449 
44 
Isopropyl alcohol. 
405 
Butyl alcohol. 
570 
41 
49 
Isobutyl alcohol. 
529 
Trimethyl carbinol. 
480 
Inactive amyl alcohol. 
G81 
•>7 
Active amyl alcohol. 
Dimethyl ethyl carbinol .... 
654 
527 
•mi t 
127 
It is evident that although simple quantitative relations do not exist between 
corresponding members of the different classes of isomeric alcohols, yet the magnitudes 
of the molecular viscosity work vary in a regular way with the chemical nature of 
the substances. 
A normal alcohol has a larger value of the molecular viscosity-work than an isomeric 
iso-prmiary, or iso-secondary alcohol, and an iso alcohol has in turn a larger value than 
an isomeric tertiary alcohol. Of the two primary amyl alcohols, iso butyl carbinol 
has a larger value than secondary butyl carbinol. All the values conform to the rule 
that the higher the boiling-point, the higher is the molecular viscosity work. It is 
also seen from the table that the difference between a normal and an iso alcohol 
is now about 40 units as compared with 15 in the case of other compounds. 
On comparing the values of allyl alcohol and normal propyl alcohol with those of the 
corresponding iodides, the behaviour of the alcohols is again seen to be peculiar. 
Alcohol. 
Iodide. 
Propyl . 
449 
794 
Allyl. 
434 
737 
15 
67 
From the whole of these comparisons it is clear that in the case of the alcohols the 
values of the molecular viscosity work vary largely with the chemical nature of the 
substance. In order to obtain some estimate of these variations and to see if they 
are subject to any general rule, the observed values for the branched-chain alcohols 
are, in the following table, com.pared with those calculated by means of the numbers 
4 s 2 
