(85) 



dency to crystallise from the melted mass in .^tphaeroh'tes ; with an 

 increasing carbon-content of the fatty acid-residue, these seem gene- 

 rally' to become smaller in cii'cumference. 



The formiate crystallises particularly beautifully; this substance 

 possesses, moreover, two solid modifications, as has been also stated 

 by Prof. Lehmann, who is of opinion that these two correspond with 

 the two solid phases of the cholesterol-derivative. In the phytosterol- 

 ester the sphaerolite-form is the more-labile one. 



On the other hand, when recrystallised from monobromonaphthalene 

 or almond-oil, they form under the microscope well-formed needle- 

 shaped crystals which, however, are always minute. Probably, we 

 are dealing in all these cases with polymorphism. I have also often 

 observed whimsical groroths and dendritics. 



A difticulty occurred in the determination of the melting point of 

 the normal valerate. It melts, over a range of temperature at about 

 67°. 1, but if the mass is allowed to cool until solidified, the ester 

 fuses to a clear liquid when heated to 30°. This behaviour is quite 

 analogous to that observed with a few glycerides of the higher fatty 

 acids, for instance with TrUaurln and Triinyristin by Schey. ^) 



After half an hour the melting point had risen again to 53 \// and 

 after 24 hours to 67'. After 24 hours, small white sphaerolites had 

 deposited in the previously coherent, scaly and slightly double-refrac- 

 ting layer on the object glass, whicii exhibited the dark cross of the 

 phytosterol. In order to explain this phenomenon, I think I must 

 assume a dimorphism of the solid substance. Moreover, liquid crystals 

 are formed here, as has also been observed by Prof. Lehmann. 



1) Schey. Dissertatie, Leiden (1899) p. 51, 54. 



