ed from the more expensive
spices, are frequently so much adulterated, that it is not easy to meet
with such as are at all fit for use: nor are these adulterations easily
discoverable. The grosser abuses, indeed, may be readily detected. Thus,
if the oil be adulterated with alcohol, it will turn milky on the
addition of water; if with expressed oils, alcohol will dissolve the
volatile, and leave the other behind; if with oil of turpentine, on
dipping a piece of paper in the mixture, and drying it with a gentle
heat, the turpentine will be betrayed by its smell. The more subtile
artists, however, have contrived other methods of sophistication, which
elude all trials. And as all volatile oils agree in the general
properties of solubility in spirit of wine, and volatility in the heat
of boiling water, &c. it is plain that they may be variously mixed with
each other, or the dearer sophisticated with the cheaper, without any
possibility of discovering the abuse by any of the before-mentioned
trials. Perfumers assert that the smell and taste are the only certain
tests of which the nature of the thing will admit. For example, if a
bark should have in every respect the appearance of good cinnamon, and
should be proved indisputably to be the genuine bark of the cinnamon
tree; yet if it want the cinnamon flavour, or has it but in a low
degree, we reject it: and the case is the same with the essential oil of
cinnamon. It is only from use and habit, or comparisons with specimens
of known quality, that we can judge of the goodness, either of the drugs
themselves, or of their oils.

Most of the arrow-root, the fecula of the Maranta arudinacea, sold by
druggists, is a mixture of potatoe starch and arrow-root.

The same system of adulteration extends to articles used in various
trades and manufactures. For instance, linen tape, and various other
household commodities of that kind, instead of being manufactured of
linen thread only, are made up of linen and cotton. Colours for
painting, not only those used by artists, such as ultramarine,[3]
carmine,[4] and lake;[5] Antwerp blue,[6] chrome yellow,[7] and Indian
ink;[8] but also the coarser colours used by the common house-painter
are more or less adulterated. Thus, of the latter kind, white lead[9] is
mixed with carbonate or sulphate of barytes; vermilion[10] with red
lead.

Soap used in house-keeping is frequently adulterated with a
considerable portion of fine white clay, brought f