VISCOSITY AND FLUIDITY 97
resembles an emulsion. Bose regards all "crystallin" liquids as
emulsions of very long life, 'i.e., they settle out with extreme
slowness, and he proposes an extension of the kinetic theory to
account for them. According to van der Waals, the molecules
are to be regarded as spheres; however, the molecules of sub-
stances known to form crystallin liquids do not approximate
to a spherical form but consist of two benzene rings united in
such a way as to make a rather elongated molecule. Hence, Bose
thinks that they may be better represented by ellipsoids of
revolution. As the temperature is lowered, these molecules
naturally arrange themselves with their long axes in parallel
planes. As the molecules unite to form the so-called "swarms,"
the viscosity is increased. This orderly arrangement also
causes the liquids to show double refraction.
It was shown that quite often the viscosity increases rapidly
as the temperature is raised at the clarifying point, but there is
also then an increase in the density.
It occurred to Bose, Willers, and Rauert (1909) that the
orderly "swarm" arrangement might be destroyed by measuring
the viscosity under conditions for turbulent flow. It was shown
by them in fact, that the abnormalities at the critical-solution
temperature do decrease as the transpiration velocity is increased.
But these results are not very conclusive since the measurement
of viscosity under conditions for turbulent flow has been but
little investigated. Pure liquids were studied by them under
conditions for turbulent flow and it was found that there is not a
complete parallelism between the viscosities as measured by the
two methods. In fact, there are several cases where one sub-
stance has a higher viscosity than another substance under
conditions for linear flow, but a lower apparent viscosity under
conditions for turbulent flow. No explanation seems to have
been given for this.
Tsakalotos (1910) has studied mixtures which show a lower
critical-solution temperature, triethylamine and water, and
nicotine and water, as well as amylen and aniline, and isobutyric
acid and water. He used only one or two temperatures so that
the peculiarity with which we are here concerned did not appear.
Bingham and White (1911) investigated phenol and water
mixtures with the following results. (1) The fluidity decreases