s that a beautiful red colour may be prepared from the
Lichen _Gyrophora pustulata_. _G. Cylindrica_ is used by Icelanders
for dyeing woollen stuffs a brownish green colour. In Sweden and
Norway, _Evernia vulpina_ is used for dyeing woollen stuffs yellow.
Iceland Moss, _Cetraria Islandica_, is used in Iceland for dyeing
brown. _Usnea barbata_ is collected from trees in Pennsylvania, and
used for an orange colour for yarn.

A general method for using lichens is suggested by Dr. Westring of
Sweden in his _Experiments on Lichens for Dyeing Wools and Silks_:

"The Lichens should be gathered after some days of rain,
they can then be more easily detached from the rocks. They
should be well washed, dried, and reduced to a fine powder:
25 parts of pure river water are added to 1 of powdered
lichen and 1 part of fresh quick lime to 10 parts powdered
lichen. To 10 lbs. lichen half a pound sal ammoniac is
sufficient when lime and sal ammoniac are used together. The
vessel containing them should be kept covered for the first
2 or 3 days. Sometimes the addition of a little common salt
or salt-petre will give greater lustre to the colours."

This method can be followed by anyone wishing to experiment with
Lichens.

Dr. Westring did not use a mordant as a rule. Where the same species
of Lichen grows on both rocks and trees, the specimens taken from
rocks give the better colours.

ORCHIL OR ARCHIL AND CUDBEAR are substantive or non mordants dyes,
obtained from Lichens of various species of Roccella growing on rocks
in the Canary Islands and other tropical and sub-tropical countries.
They used to be made in certain parts of Great Britain from various
lichens, but the manufacture of these has almost entirely disappeared.
They have been known from early times as dyes. They give beautiful
purples and reds, but the colour is not very fast. The dye is produced
by the action of ammonia and oxygen upon the crushed Lichens or weeds
as they are called. The early way of producing the colour was by
treating the Lichen with stale urine and slaked lime and this method
was followed in Scotland. Orchil is applied to wool by the simple
process of boiling it in a neutral or slightly acid solution of the
colouring matter. 3% Sulphuric acid is a useful combination. Sometimes
alum and tartar are used. It dyes slowly and evenly. It is used as a
bottom for Indigo on wool and also for compound shades on