264 Transactions. — Chemistry/. 



To the clear filtrate basic lead acetate was added so long as it occasioned a 

 precipitate. [This precipitate, consisting chiefly of the lead-salts of organic 

 acids, will be referred to further on in this section of the report, under the 

 heading F.] This precipitate was then filtered off", and the clear filtrate 

 purified further, as follows : — Excess of hydrosulphuric acid was passed into it, 

 it was filtered, warmed, and finally evaporated in vacuo. The syruppy residue 

 of this evaporation consisted mainly of sugar, but contained also a large 

 proportion of the total quantity of the bitter principle present, as well as some 

 acid substances. To separate the bitter principle, the concentrated liquor was 

 shaken up with ether, in which the acids as well as the sugar are almost entirely 

 insoluble. The ethereal solution was then decanted ofiT and evaporated : it 

 left a residue which was slightly yellow in colour and resinous in appearance. 

 On boiling this residue with much water and a little powdered animal char- 

 coal, the greater part of the bitter principle was withdrawn from solution by the 

 charcoal, which latter substance again yielded it up to strong boiling alcohol. 

 Thus extracted, the bitter principle of Phormium tenax is colourless, and 

 exhibits but veiy doubtful traces of crystallization. Its bitter taste is not 

 disagreeable nor persistent. It does not come within the scope of a chemical 

 report to discuss the possible medicinal value of this bitter principle, but it 

 may be assumed that it possesses active properties, and I am inclined to think 

 that these are tonic rather than poisonous. 



E. — Colouring Matters. 



The chief colouring matter of the Phormium leaf is the usual green 

 colouring matter of plants, namely, chlorophyll. This substance is extracted 

 by alcohol from the dry leaves in abundance, but it is left behind in an altered 

 or decomposed state when the alcoholic extract is evaporated, and then boiled 

 out with water. It is not necessary to dwell upon the properties of so 

 universally distributed a substance as chlorophyll, particularly as there seems 

 little or no probability of its being turned to account in the arts. Its interest 

 in connection with the present inquiry appears wholly to lie in the following 

 consideration. In preparing Phormium fibre the chlorophyll may give rise to 

 stains or discolourations if it be not rapidly and thoroughly removed in the first 

 processes to which the leaves are submitted ; for though chlorophyll may be 

 removed easily from the fresh leaf-cells containing it, yet this colouiing matter 

 is susceptible of certain changes, the products of which, having a dull green or 

 brown colour, are not very easily dissolved from the stained fibre. They seem 

 to find their way into the central cavities of the fibres, from which it is 

 difficult to remove them. But the chlorophyll is accomj)anied by another 

 colouring matter, which appears to give rise to certain reddish-brown stains on 

 the Phormium leaf and fibre. I am inclined to think that this colouring 



