( ±79 ) 



liquid appears to be identical with A, and to be pseudo-isotropous 

 by homoeotropism only. The optical axes of the doubly-refracting 

 modification A again place themselves perpendicularly on the surface 

 of the covering glass. On continued cooling A becomes increasingly 

 thicker; at last a movement in the mass can be seen only on stirring. 

 After a longer time there are formed from numerous centres in this 

 tenacious mass thin, radiated spherolites. whose velocity i»t* growth 

 is but very small. When a number of these spherolites have formed 

 and the mass is then heated carefully, the spherolites do not melt, 

 but actually increase owing to the greater crystallisation-velocity. 

 Soon afterwards — however, they melt, on further heating, to the 

 doubly-refracting phase A, where the circumferences of the spherolites 

 and the black axial crosses arc preserve)/ for some time; so that the 

 whole much resembles a liquid mozaic. Subsequently the phase B 

 reappears and afterwards the isotropous fusion L. The whole series 

 of phases is traversed in a reversible manner; the liquid phase A, 

 however may be so much undercooled, that a proper meltina or 

 solidifying point of the substance cannot be given. In larger quantities 

 of the substance, the crystallisation does not set in till after some 

 hours, and the substance turns first to a horny mass, which always 

 remains doubly -refracting to finally exhibit local, white spots, from 

 which the spherolite-fonnation slowly spreads through the entire 

 mass. One would feel inclined to call this transformation of liquid- 

 anisotropous into crystallised substance a continuous one, if it were 

 only possible to observe, even for a moment, the intermediate con- 

 ditions in that transition. As the matter cannot be settled by direct 

 experiment, the transition must be put down, provisionally as a 

 discontinuous one. 



In this case also, and the same applies to the other cholesterol- 

 esters as well, the spherolite-structure of the solid phase is of great 

 importance for this entire transformation of undercooled, anisotropous- 

 liquid condition into the solid one. At the end of this communication 

 I will allude briefly to a few cases from which the particular signi- 

 ficance of the spherolite-structure in the transitions between aniso- 

 tropous-liquid and anisotropous solid phases is shown also plainly in 

 a different manner. 



§ 10. Cholesterol- Pabnitate behaves in quite an analogous manner ; 

 I observed one solid phase and three liquid conditions .4, B and L; 

 as in the case of the laurate, B is generally observed onl} r on 

 warming. The succession of the liquid and solid phases takes place, 

 however comparatively rapidly, so that a real solidifying point may 



32* 



