216 NOTES ON THE IDENTIFICATION 



crystal is an independent tint (see Fig. ii). 



Helenine can scarcely be said to crystallise at all. The alcoholic 

 residue refuses to dry completely at ordinary temperatures. 

 The crystals are mere arborescent sprays (Fig. 32). 



Helleborine crystallises as the hydrochlorate from an acid 

 solution, by dissolving helleborine in HCl and allowing it to 

 evaporate spontaneously. The crystals are white under 

 polarised light (Fig. 31). 



Hyoscyamine crystallises as the hydrochlorate from water. The 

 crystals are best viewed by ordinary light, and resemble crystals 

 of common salt (Fig. 33). 



Hemidesmine crystaUises from water in needles of a peculiar shape 

 — spiked, branching, and flattened (Fig. 34). 



Mannite crystallises from water in feathery sprays, resembling 

 those of cinchonidine sulphate, q.v. (Fig. 35). 



Picric Acid. — The crystals of picric acid deposited from etherial 

 alcohol are yellow by reflected light, but under the polariser 

 present most remarkable forms. The crystals are rectangular 

 and fringed with the most curious arborescent processes. 

 Some forms resemble moss, others branches of fir. Altogether 

 it is a unique object. Best seen with selenite (Fig. 36). 



Piperine crystaUises well from a mixture of alcohol and ether, in 

 four-sided monoclinic prisms. The crystals appear as if 

 marked upon their surface, owing to the varying thickness, or 

 partial adherence of other crystals (Fig. 37). 



PiCROTOXiNE, both from alcohol and water, forms ill-defined 

 crystals (four-sided prisms) grouped in stars. These, for the 

 most part, do not depolarise because they are globular in form, 

 and, consequently, nearly opaque. A few isolated crystals 

 depolarise (Figs. 38, 39). 



QuASSiNE forms very minute crystals when deposited from ether. 

 I am not quite certain to what system they belong. A power 

 of 210 is not sufficient to determine this (Fig. 40). 



RuTiNE crystallises from hot water in a network of fine needles 

 (Fig- 41)- 



