( -±74 ) 



"phenomena of' retardation" play a great róle ; moreover the enormous 

 undercooling which the phase A can undergo without transformation, 

 proves this satisfactorily in the majority of these esters. 



The different behaviour of' the laurate on melting and on cooling 

 the fused mass is so characteristic, that no doubt can be entertained as 

 to the irreversibility of each series of transformations. Fuller details 

 will be given below in the micro-physical investigation. 



§ 3. Choleslerol'Nonylate tonus at 90° an isotropous fused mass of 



the consistency of paraffin oil; on cooling to 89°5 a stable, greyish. 

 doubly-refracting liquid B appears which, gradually thickening, passes 

 into a second strongly doubly-refracting liquid phase .1. — which trans- 

 formation is accompanied with a brilliant display of colours. All three 

 liquids are, however, quite stable within each specific temperature- 

 traject. On melting, as well as on cooling the substance, they succeed 

 each other in the proper order. 



The viscous, strongly doubly-refracting, liquid phase A now 

 becomes more viscous on cooling, and is finally transformed into a 

 horny, transparent mass which exhibits no trace of crystallisation. 

 Even after some hours, the often still very tenacious mass has not 

 got crystallised. In the case of' this substance it is therefore impos- 

 sible to give the solidifying point or the exacf temperature at which 

 the heated mass begins to melt. The reason of fhis is, that the doubly 

 refracting liquid -1 can be undercooled enormously and passes gra- 

 dually into the solid condition without crystallising. 



As the micro-physical research has shown, a spherolite-formation 

 occurs afterwards suddenly in the mass, which ultimately leads to the 

 complete crystallisation of the substance. 



The velocity, with which such spherolites arc; formed appeared in 

 some cases not to exceed 0.000035 — 0.000070 m.m. per second! 



§ 4. C/wlesterol-Myristate, at 80°, is still an isotropous, paraffin 

 oil-like liquid. On cooling, it gradually becomes viscous; at about 

 82. °G the glycerol-like phase then turns, with violet-blue opalescence, 

 into a thick, strongly doubly-refracting mass A which, gradually 

 assuming a thicker consistency, is finally converted into a horny 

 mass, without any indication of a definite solidifying point. In this 

 respect the substance is quite analogous to the previous one. On the 

 other hand, on being melted, it behaves more like the laurate, in so 

 far as it is converted into a double-refracting liquid B, before passing 

 completely into L. The transition temperature cannot be determined 

 sharply, but I estimate it at about 80°. 



