460 IBIDEM. 



anhydride, shaking the distillate with ether, and evaporating 

 the ether in a current of carbonic anhydride, the essential oil 

 was obtained as a very mobile, scarcely yellowish coloured 



m 



becoming thick and brown by absorption of oxygen from the 

 atmosphere, and giving upon analysis figures correspondin 





with the formula C^°H^^. Crocin was obtained by treating 

 an aqueous extract, made without heat from saffron previously 

 exhausted with ether, with purified animal, charcoal, which 

 removed all the colouring matter ; then filtering, washing and 

 drying the charcoal, boiling it with 90 per cent, alcohol and 

 filtering. Upon removal of the alcohol the crociu was left 

 as a brittle yellow-browjti mass, yielding a pure yellow powder, 

 freely soluble in water and dilute alcohol, less soluble in absolute 

 alcohol, and giving up only traces to ether • With con- 

 centrated sulphuric acid it gave a deep blue solution, passing 

 to violet, cherry red, and finally to brown ; with nitric acid a 

 deep blue, passing almost immediately to brown ; with hydro- 

 chloric acid it underwent no change of colour. Acetate of lead 

 produced no precipitate in a solution of crocin in the cold, but 

 on warming the solution, decomposition at once took place, and 

 the liquid then reduced Fehling's solution. As previous 

 workers used lead acetate in the separation of crocin, Ilcrr 

 Kayser supposes that their product always contained crocctin. 

 He attributes to pure crocin the formula C^^H"^^0-«, and to 

 crocctin C'^^H^'^O^, the decomposition being represented by 

 the following equation : 



An ethereal extract of the residual saffron yielded a crystalbne 

 bitter substance, freely soluble in water and alcohol, less easily 

 in chloroform and ether, and melting at 75° This has been 

 named '' picrocrocin/' and is represented by the formula 

 (^301X61017^ It presents the interesting character that when 

 warmed in aqueous solution with load acetate, lime or baryta 

 water or acid, it splits up into sugar and an essential oil, 



which has a strong odour of saffron and the composition of a 

 terpene. 



