120

FLUIDITY AND PLASTICITY

absolute) is therefore 328.9/142.6 = 2.31. In Table XXX are
given the observed and calculated absolute temperatures corre-
sponding to the fluidity of 200 and the association calculated
therefrom for some typical associated compounds. The slopes
of these curves are also given in the fourth column.

TABLE XXX.—ABSOLUTE TEMPEEATUEES AND SLOPES OF SOME ASSO-
CIATED COMPOUNDS CORRESPONDING TO A FLUIDITY OF 200 C.G.S. UNITS

Substance
Absolute temperature for (<f> == 200) observed
Absolute temperature for (<£ = 200) calculated
Slope for (<£ = 200)
Association

Water ...............
328 9
142.6
3.04
2.31

Formic acid
(380 2)
185 5
(2.18)
2.05

Acetic acid
363 8
208 2
2.06
1.77

Propionic acid .
362 0
230 9
1.92
1.57

Butyric acid .......
381 6
253.6
1.92
1.57

Isobutyric acid .......
371.6
246.0
2.00
1.51

Methyl alcohol .......
305.2
165.3
2.78
1.84

Ethyl alcohol.
343 4
188 0
3 24
1.83

Propyl alcohol .....
365 6
210 7
3.76
1.74

Butyl alcohol ........
377 0
233 4
3.44
1.62

Ethyl formate ........
273.8
230.7
2.40
1.19

Ethyl acetate
284 0
253 4
2 50
1.12

Ethyl propionate ......
298.1
275.1
2.44
1.08

The test of our complete process of reasoning comes now
when we compare the association obtained in this way with the
values which have been obtained by other methods. The results
of this comparison are shown by Table XXXI.
So far as one is able to judge, the result seems to be all that
could be desired. There are almost invariably values given by
other methods which are both higher and lower than our values
and such a degree of association is certainly not inconsistent with
our knowledge of the chemical conduct of these substances.
The fluidity method of obtaining the association factor seems to
be freer from assumptions, to which questions maybe raised, than
other methods which have been proposed, and it is to be hoped
that it may prove useful in calculating this very important fac-
tor. If eventually we are able to obtain thoroughly consistent