190 
A similar question arose in 1902 in regard to the phenomenon of 
Masorana') based on the fact that a colloidal solution of Fe(OH), 
becomes birefractive in a magnetic field and exhibits dichroism. 
Corton and Mouron *), who have studied this phenomenon very 
accurately come, after full discussion of the different possibilities, 
to the conclusion that the explanation founded on the assumption 
of equally-directed, elongated but themselves isotropic particles is 
not satisfactory and that we must assume that the particles them- 
selves are anisotropic. The idea that they consist already of small 
crystals seems to them a very likely one. 
DiesserL HORST and FREUNDLICH do not express themselves positively 
on this question. At the discussion following a lecture of the last 
named at the meeting of the Bunsengesellschaft*) the question 
aroused great interest, without, however, an agreement being 
arrived at. 
For our coneeption as to the amorphous condition and as to the 
nature of colloidal solutions it is of much importance. It also bears 
on the question what dimension the particles must have in order 
to exhibit crystalline properties and whether there is a continuity 
between free molecules and crystals. _ 
In this respect F. and D. already pointed to the great similarity 
which this vanadium oxide sol exhibits with the liquid erystals. 
According to the structural-chemical investigations of VORILÄNDER *) 
the molecules of these anisotropic liquids must have an elongated 
form. Also LEHMANN ®) points to this and Bosr ®) explains the aniso- 
tropism of these liquids by assuming that the elongated molecules 
unite to clusters wherein they all have the same direction. 
Finally, Frrunpiicn’) favours most the idea that the elongated 
particles of the V,O, sol might be similar clusters of equally-directed 
molecules which, however, may not yet be called crystals, a link 
between amorphous and erystalline. It appears to me that such an 
assumption causes an unnecessary complication and that it is simpler 
to look upon these needles as being already crystals. 
In this case there must be a continuity between these ultra- 
micrones and the macro- or microscopically visible crystals. 
1) Rendiconti Acc. Lincei XI (1902)!, 536; XI (1902)2, 90. 
2) Ann. de chim. et de phys. (8) 11, 145, 289 (1907). 
3, Zeitschr. f. Electrochem. 22 27 (1916). 
4) Bes. d. Deutsch chem. Ges. 40, 1970 (1907). 
5) Die neue Welt der flüssigen Krystalle 1911, 187. 
6) Phys. Zeitschr. 9, 708. 
1) Z.f. Elektrochem, 22, 32. 
