Note on the Molecules of Liquid Crystals. 
53 
cially because only one axis remains in a fixed direction. Under such 
conditions the dispersion will be equal in all directions." 
In a series of later experiments the same substance (paraazoxyanisol) 
was placed between two pieces of thin mica. The object of these 
experiments was to find whether the molecules of the liquid substance 
i 
<7 0^0 
m' 
4 
Magnetic Field. 
Fig. 2. 
will assume a space-lattice under the influence of the neighbouring 
molecules of mica. Observations on the substance in a magnetic field 
showed that the orientating power of the mica sheets is much greater 
than of glass plates. A much greater magnetic field is required to 
Magnetic Field. 
Fig. 3a.— Vertical Section. 
Magnetic Field. 
Fig. 36. — Horizontal Section. 
orientate the molecules. The available field of 6,000 gauss does not 
cause complete orientation, whereas 3,000 gauss cause an apparently 
complete orientation when the substance is placed between glass plates. 
On using thicker layers the substance shows that there is a magnetic 
* If we assume that S^Iw round the magnetic axis is zero where I and w is not 
zerp. 
