186 REVIEWS. 
claims or importance of this limited but interesting branch of economic 
botany :— 
I. Experiment on the small scale shows that many native and foreign 
Lichens, which are at present unknown in commerce, and are unapplied 
to our arts and manufactures, furnish the same (or similar) dyes, as those 
species which are usually employed in the manufacture of orchil, cudbear, 
and litmus. 
II. Many of these species grow abundantly, or reach their acme of 
perfection, in cold climates; several are plentiful on the mountains of 
Scotland, Ireland, and Wales, where they could be collected cheaply and 
easily ; all can be gathered and transported with little or no skill or 
labour. 
III. Whereas in the manufacture of orchil Roccella tinctoria, and in 
that of cudbear and litmus Lecanora tartarea, were the species formerly 
chiefly used in this or other countries, now British manufacturers have 
introduced many other dye-lichens, either as substitutes or adulterations. 
IV. Some of these were formerly collected to a considerable extent in 
different districts of this country for the Glasgow and London markets, 
e. g. Lecanora tartarea, the so-called ‘ Cudbear’ Lichen. 
V. Many species are, or have been, used to furnish dyes by the natives 
or peasantry in almost all parts of the world. In evidence whereof I 
need only refer to the ‘ crotals’ of Scotland, the ‘ stane-raws’ or ‘ stone- ’ 
rags’ of England, Ireland, and Wales, the ‘ korkalett’ and ‘ scrottyie’ of 
Shetland, the ‘ beettelet,’ the ‘ sten-mossa,’ ‘ alaforel-laf,’ ‘ bjork-laf,’ etc., 
of Sweden and Norway, the ‘ Perelle d’ Auvergne’ of France, the ‘ chul- 
cheleera’ of India, the ‘ caranja’ and ‘ Jaffna moss’ of Ceylon, and the 
Usnea barbata in South America; and, for general information there- 
anent, to Table I. There is a probability that dye-lichens continue to be 
used in some parts of our Highlands and Islands, where they were for- 
merly employed to a great extent, from the fact that in a collection of the 
vegetable products of Scotland, at the Exhibition of 1851, yarns dyed 
by the following ‘ crotals’ were exhibited :— 
Tsidium corallinum [white crottle or crotal]. 
Lecanora parella [light 3 At 
Sticta pulmonacea [light crottle di; 
Parmelia physodes [dark Fs il: 
», omphalodes [black a a 
Besides »  parietina, etc. 
VI. The dye-lichens thus used by manufacturers or by the peasantry 
are the very species which are proved (as a general rule), by experiments 
on the small scale, to be richest in colouring matters : hence, by analogy, 
the probability that other species, which experiment has also determined 
