PAPAVER
somniferum.
Estimation of Value of Opium.
MANUFAC-
TURE.
Valuation.
Texture.
68
Extracted from the Dictionary of
Aroma .
finger on a white earthenware plate. Here it is that we see clearly the
various shades of chestnut, reddish-brown, dark brown or mahogany, but
never black. When rubbed between the fingers opium displays a shining
surface and a waxy lustre.
" The colour of opium is a valuable indication as to its purity.
" TEXTURE.—Like consistence and colour the drug delivered at the Gov
-ernment Factories may be said to differ, one sample from another, in tex
-ture. At the two extreme poles of variation there are the distinctly granu
-lar, and the perfectly homogeneous, and the bulk of the produce lies, as to
texture, somewhere intermediate between those extremes.
"The primary causes of variation, into which our enquiry does not ex-
tend, are undoubtedly due to differences in soil, and to conditions of
weather obtaining at the time of collecting the drug ; they are also due, to
some extent, to manipulation of the drug after collection. A light-coloured,
chestnut or reddish-brown variety of the drug, which is free from pasewha,
will, as a rule, be found to be distinctly granular, while the dark, or black-
-ish-brown variety, which has more or less of pasewha in its composition, or
an excess of moisture, will, on the other hand, tend to the homogeneous
type.
"Ordinary manipulation, without the aid of sophistication, has little
effect on texture, but long-continued manipulation will affect it materially.
The presence of pasewha, again, affects it in a very marked degree, and so
does an excess of moisture.
"As already explained under the head " consistence " to the presence of
pasewha in varying quantities is due the merging, more or less, of the tears
into each other whereby the granular nature of the drug passes by imper-
ceptible gradations to the homogeneous. The presence of pasewha also
alters the dull waxy appearance of the drug to one that is more or less
smooth and shiny, adding to it tenacity, and making it more glutinous.
Ordinarily, opium, free from pasewha, is moderately ductile, but the pre-
sence of pasewha, by adding tenacity, increases also the ductility of the
drug. This is seen by drawing out with both hands opium of high
sistence. If free from pasewha it will be found to be ductile to an extent
varying according to consistence, with a uniform and minutely granular
texture. When there is pasewha present this ductility is increased, while
the granular texture is less marked, according to the proportion of pasewha
present. The drug when thus drawn out breaks with an irregular fracture ;
it adheres to the fingers, is viscid, and of a plastic nature. The texture of
the drug is also well seen in high consistence opium when a section is
exposed with a spatula.
"Opium of the lower consistences—below about 66°—being in a some--
what fluid state, will not draw out at all but breaks off with ragged edges.
Its texture is subject to change, under the same conditions, as in opium of
higher consistences.
"The texture of any given sample of pure drug is always uniform. A
practised eye can at once detect any irregularity, and where such exists it
betrays the presence of a foreign substance in the composition of the drug.
"AROMA.—Chemistry has not yet isolated the volatile odorous principles
of opium. Its aroma, however, is peculiar and characteristic. Some con-
-sider it not unpleasant, while others relegate it to the class of disagreeable
odours. In well-prepared, fresh drug the aroma is decidedly fruity, but it
varies with age, and is even said to vary somewhat with the description of
soil on which the plant is grown, and with the manure used.
"Careless preparation of the drug, such as its collection or manipulation
in plates not scrupulously clean, or allowing it to come in contact with
ani mal subst ances, such as bl adder s f or st or i ng i t away i n, or keepi ng i t i n