osing them
to light and air, on racks or shelves, or on clean well-ventilated
barn floors, or lofts. They should be spread out thinly and turned
occasionally from day to day until completely cured. When this point
is reached, in perhaps three to six weeks, the roots will snap
readily when bent. If dried out of doors they should be placed under
shelter at night and upon the approach of rain.

Some roots require slicing and removing fibrous rootless. In
general, large roots should be split or sliced when green in order
to facilitate drying.

Barks of trees should be gathered in spring, when the sap begins to
flow, but may also be peeled in winter. In the case of the coarser
barks (as elm, hemlock, poplar, oak, pine, and wild cherry) the
outer layer is shaved off before the bark is removed from the tree,
which process is known as "rossing." Only the inner bark of these
trees is used medicinally. Barks may also be cured by exposure to
sunlight, but moisture must be avoided.

Leaves and herbs should be collected when the plants are in full
flower. The whole plant may be cut and the leaves may be stripped
from it, rejecting the coarse and large stems as much as possible,
and keeping only the flowering tops and more tender stems and
leaves.

Both leaves and herbs should be spread out in thin layers on clean
floors, racks, or shelves, in the shade, but where there is free
circulation of air, and turned frequently until thoroughly dry.
Moisture will darken them.

Flowers are collected when they first open or immediately after, not
when they are beginning to fade. Seeds should be gathered just as
they are ripening, before the seed pods open, and should be winnowed
in order to remove fragments of stems, leaves, and shriveled
specimens.

The collector should be sure that the plant is the right one. Many
plants closely resemble one another, and some "yarbs," contrary to
the popular impression, are deadly poison--nightshade (belladonna)
and the wild variety of parsnips, for instance. Therefore, where any
doubt exists, send a specimen of the entire plant, including leaves,
flowers, and fruits, to a drug dealer or to the nearest state
experiment station for identification.

Samples representative of the lot of drugs to be sold should be sent
to the nearest commission merchant, or drug store, for inspection
and for quotation on the amount of drug that can be furnished, or
for information as to where to send the article.

In