FLUIDITY AND TUK CHEMICAL COMPOSITION 111
into two classes. In the first tho deviations are to be attributed
to chemical constitution, as similar disturbing effects may be
detected in the magnitudes of other physical properties which do
not seem to be affected by molecular complexity. In the second
are those substances like the acids, water, and the alcohols, for
which the disturbing factor is, no doubt, molecular complexity,
the effect produced in this way, in the case of the alcohols, being-
dependent upon their chemical nature/7 Thorpe and Rodger
have done great service in stating the problem before us so
clearly. At a subsequent point in our discussion, we will show
how by a different method of comparison it is possible to largely
avoid the first cause of discrepancy given above, and how then
with only one unknown quantity remaining, it is possible to get a
proximate solution of the problem.
TABLE XXIV.—MOLECULAR VISCOSITY WORK CONSTANTS AT SLOPE
0.000,032,3
Hydrogen........................................ — 34
Carbon.......................................... 148
Hydroxyl-oxygcn, C-O-H.......................... 100
Ether-oxygen, C-O-C.............................. 43
Carbonyl-oxygen, C = 0.......................... — 19
Sulfur, C-S-C..................................... 144
Chlorine (in monochlorides)........................ 89
Chlorine (in dichlorides)........................... 82
Bromine (in inonobromides)........................ 151
Bromine (in dibromides).......................... 148
Iodine........................................... 218
Iso-grouping..................................... — 8
Double linkage................................... —- 95
Ring-grouping.................................... —369
The effect of chemical constitution upon viscosity has been
employed to good effect in the solution of several much-mooted
chemical problems by Dunstan and Thole and their co-workers.
Thus Thole (1.910) observed a steady increase in the viscosity of
freshly distilled ethyl acetoacetate owing to the gradual enoliza-
tion of the kctonic form. Hilditch and Dunstan (1911) have
observed that the presence of Thiele's " conjugated double bonds7'
in compounds produces a great increase in the viscosity. Thole
(1912) has shown that the viscosity method can be used to dis-
tinguish between geometrical isomcrides like maleic and furnaric