under the
forms of cudbear or litmus.

HENNA (_Lawsonia inermis_), is an important dye-stuff, and the
distilled water of the flowers is used as a perfume. The Mahomedan
women in India use the shoots for dyeing their nails red, and the same
practice prevails in Arabia. In these countries the manes and tails of
the horses are stained red in the same manner. The _Genista tomentosa_
yields red petals used in dyeing, and containing much tannic acid.

ORCHILLA WEED.--The fine purple color which the orchilla weed yields,
is in use as an agent for coloring, staining, and dyeing. About 30,000
lbs. is obtained annually in the island of Teneriffe. 460 arrobas (or
115 cwt.) of orchilla were exported from the Canary Isles in 1833. In
1839, 6,494 cwts. paid duty, and 4,175 cwts. in 1840. The average
imports of the three years ending with 1842, was 6,050 cwt. A little
comes in from Barbary and the islands of the Archipelago.

Dr. W.L. Lindley, in a very interesting paper, read before the
Botanical Society of London, in December, 1852, on the dyeing
properties of the lichens, stated--

The subject of the _colorific_ and _coloring_ principles of the
lichen has, within the last few years, attracted a due share of that
attention which, has been increasingly devoted to organic chemistry.
Since 1830, Heeren, Kane, Schunck, Rochleder and Heldt, Knop,
Stenhouse, Laurent and Gerhardt, have published valuable papers on
these principles; but, here again, we have to regret the great
discrepancy in the various results obtained, and there is therefore,
here also, imperatively demanded re-investigation and correction
before _any_ of the results already published can he implicitly
relied upon, and before we can have safe data from which to
generalise. I have no doubt that a great proportion of the obscurity
overhanging this subject depends on the circumstance that many of
the chemists, who have devoted attention to the color-educts and
products of the lichens, were not themselves botanists, and have
therefore probably, in some cases at least, analysed species under
erroneous names, and also because their investigations have
comprehended a much too limited number of species.

Their utility in the arts, and especially in dyeing--including the
collection of a series of the commercial dye lichens, _i.e._, those
used by the manufacturers of London, &c., in the making of o