( 703 ) 



Of colour phenomena during one of these transitions, absolutely 

 not hi ui/ is noticed. 



If, however, we starl from the phase L and allow the same to 

 cool, we lirst notice the doubly -refracting phase />', which on further 

 cooling, amid violent sudden currents of the mass, passes into a 

 much more strongly doubly-refracting liquid A, which on continued 

 cooling crystallises suddenly, also amid very violent currents, to an 

 aggregate of flat needles, glittering in vivid interference colours. These 

 in turn, rapidly assume a spherolite structure so that the solid phase 

 S itself appears to be also dimorphous and monotwpous, as the tlat 

 needles are not reobtained on warming the spherolitic mass. The 

 transformation of A into these needles, during cooling, is accompanied 

 with the most vivid display of colours. Under the microscope these 

 may be recognised by the dark-green colour of the background of 

 the field of vision ; with the naked eye, however, with incident 

 light, that colour-display commences with a brilliant violet gradually 

 turning into blue and finally into a radiating green when the 

 mass crystallises. I have never noticed red or yellow colours with 

 incident light. These phenomena return in the same order when the 

 experiment is repeated. 



That the phase A really exhibits the behaviour of a stable phase 







Fig. 1. 

 Schematic p-l-diagram for Dihydro-cholesterol-n-butyratc. 



