Chap. XV. 
MR. WARRINGTON'S REMARKS. 
241 
is shown in some observations made by Mr. Warrington, 
of Apothecaries' Hall, in his paper which I have already 
quoted. 
The question presents itself, then,*' says Mr. War- 
rington, alluding to the variation of physical and chemical 
properties in green and black teas, "from whence do 
these distinguishing peculiarities arise, and to what are 
they to be attributed? From observations made in 
other directions, in the course of the routine work of the 
establishment to which I am attached, I had formed in 
my own mind certain conclusions on this subject. I 
allude to the exsiccation of medicinal herbs ; these are 
for the most part nitrogenous plants, as the Atrojpa 
belladonna, the Hyoscyamus niger, the Conium 
maculatum, and others. The plants are brought to 
us by the growers or collectors from the country, tied 
up in bundles, and when they arrive fresh and cool they 
dry of a good bright green colour ; but on the contrary, 
it is found that if they are delayed in their transit, or 
remain in a confined state for too long a period, they 
become heated, from a species of spontaneous fermenta- 
tion, and, when loosened and spread open, emit vapours, 
and are sensibly warm to the hand : when such plants 
are dried, the whole of the green colour is found to have 
been destroyed, and a red-brown and sometimes a 
blacJcish-brown result is obtained. I had also noticed 
that a clear infusion of such leaves evaporated carefully 
to dryness was not all undissolved by water, but left a 
quantity of brown oxidised extractive matter, to which 
the denomination Apothem has been applied by some 
chemists ; a similar result is obtained by the evaporation 
VOL. II. M 
