108 ON THE PRESENT USE OF LICHENS AS DYE-STUFFS. 
that may involve heavy pecuniary loss, and implies a great commercial 
risk, it is not surprising that new materials and new processes are 
adopted with unusual tardiness or caution. This experience of ma- 
nufacturers is opposed to the views of chemists and botanists, both of 
whom appear to have firm faith in the trustworthiness of tests of 
colorific value applied on the small scale. The best-known of these 
tests in this country are the hypochlorites of lime or soda as recom- 
mended by Dr. Stenhouse, of London. The former has lately been 
adopted by the distinguished lichenologist Dr. Nylander, of Paris, who 
expresses himself in the following very strong terms of the simple 
application of a drop of solution of hypochlorite of lime on a glass 
stirrer to any given sample of “Orchella weed :"—** Thus are we 
enabled to say what is the quantity of this colourable matter, which the 
different species of the genus contain, it being, in fact, a sort of imme- 
diate analysis." The results of my own experiments on the colorific 
properties of Lichens, which were published between 1853 and 1855, as 
well as of certain other more recent experiments not yet published, 
lead me to agree with the manufacturers, and not with lichenologists 
and chemists. 
In British commerce and in British manufacture Orchill occurs as a 
liquor— concentrated or not—and as a paste, of various shades of red 
and blue, with the intermediate gradations of purple and violet. 
While Orchill has, of late, been apparently less used than formerly in 
this country in the colouring of silk, cotton, and woollen goods, it seems 
to have been more and more largely applied to the dyeing of carpets 
and leather with shades of brown and maroon, as well as mauve and 
magenta. While Orchill is the form usually employed by professional 
dyers, Cudbear is that generally used in domestic dyeing. I found, 
for instance, that the latter is still largely imported into, and used in, the 
Hebrides, Orkney, and Shetland for the dyeing of home-made yarn. 
udbear appears to be prepared from the same sources as Orchill: from 
which it differs only in that it contains powdered lichen as well as 
its red extracted colouring-matter, the latter requiring to be dis- 
solved out, by boiling, for use. 
e market value of “ Orchella weeds” has fallen from £300 to £70 
or £30 per ton,—a circumstance which is attributable on the one hand 
to competition of Orchill with the coal-tar and other abundant and 
cheap colours of home production, and on the other to the now nume- 
