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Notes on the Colouring Matter of Drosera 

 Whittakeri. 



By Edwakd H. Een^nie, M.A., D.Sc. 



[Eead February 1, 1887.] 



The little carnivorous plant known by the name Drosera 

 Whittakeri grows plentifully on the hills in the neighbourhood 

 of Adelaide. At the termination of the underground stem, 

 some three or four inches long, is found a tuber which contains 

 a considerable quantity of red colouring matter. My attention 

 was first called to it by Professor Tate, who informed me that 

 Mr. Gr. Francis had partially examined the red substance. The 

 latter gentleman was good enough to show me the specimen he 

 had prepared, and also some pieces of silk which he had dyed 

 by means of it, but he did not carry out a complete investiga- 

 tion. As the matter seemed to me of some interest from a 

 chemical point of view, I collected a quantity of the tubers 

 with a view of examining the colouring matter more closely. 



An examination of the tubers shows that they all consist of a 

 soft nucleus full of a reddish juice, surrounded by a series of 

 more or less dried layers. Between these layers is collected a 

 red substance, which appears in irregular patches. 



The tubers were crushed as a whole and treated with strong 

 rectified spirit till the latter extracted no more colour. The 

 spirit was then almost entirely distilled off and the residue 

 mixed with a little water and allowed to stand for a few hours. 

 A deep red solution remained, but by far the greater part of 

 the red matter was found as a granular sediment at the bottom 

 of the liquid. This was filtered off and dried. 



A preliminary experiment having shown that it was volatile, 

 it was sublimed, the subliming apparatus consisting simply of 

 an ordinary saucepan, with a shallow iron dish for lid, a large 

 glass funnel (the neck closed with a cork) being inverted over 

 the latter. In this manner a crystalline mass was obtained of 

 a brilliant scarlet colour, which, on close examination, appeared 

 to consist of at least two substances, for on dissolving a little 

 in ether and evaporating a few drops on a slide, the residue 

 was seen under the microscope to consist of two kinds of 

 crystals, some yellower and longer than the others. 



A few trials soon showed that one of these substances is 

 much more soluble in glacial acetic acid, and indeed in most 

 solvents, than the other. By repeated crystallization from 



