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 вие 
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 off 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coal, the greater part of the bitter principle was withdrawn from solution by the 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 very 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 chlor 
ophyll may be 
removed easily from the fresh 
leaf-cells containing it, yet this colouring 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 accompanied 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 
