THAXLOGEX^. 719 



receive the name of the country from whence they have been derived. 

 Orchella vreed is extensively used in the manufartnre of purple and red 

 colours, called oirhil or archil and cudbear. In Holland the bine colour, 

 called lif77iiis, is also prepared from the same lichens. Other lichens, as species 

 of Lecanora, Gyrophora, Parmelia, Variolaria, dr., are also --ometimes 

 employed in Bi-itain and elsewhere in the manufacture of orchil. &c. (See 

 these species.) Orchil and cudbear are used for staining and dyeing purple 

 and red colours, and also occasionally as tests for acids and alkalies. Litmus 

 is employed as a test for alkalies, acids, and some salts ■vsith a basic reaction. 

 A decoction of orcheUa Tseed possesses mucilaginous, emoUient, and demtd- 

 cent properties, and has been used in coughs, catarrhs, &c. 



Sticta puhnonaria. Tree Lung--wort, Oak-lungs.— This lichen possesses 

 tonic and nutritious properties, resembling in these respects the Cetraria 

 islardica. In Siberia, it is used instead of hops for imparting bitterness 

 to beer. It is also employed in France, &c. for the production of a bro^vn 

 dye. 



Variolaria. V. dealbata and V. oreina are used for the production of 

 orchil in France. 



Natiiral Order 294. FrxGi. — The Mushroom Order. — Diap- 

 nosis. — Parenchymatous celluL\r plants, producing their fructifi- 

 cation in the air; growing in or upon decapng or living organic 

 substances, and nourished through their vegetative structure 

 called the spawn or mycelium (fffs. 4-6, and 827). Fructifica- 

 tion various. (See pages 377—380, and figs. 827-830.) 



Distribution, ^'c. — They abound in all parts of the world 

 except in the very coldest, where their spawn would be destroyed. 

 Examples of the Genera : — Agaricus, Tonila, Puccinia, Uredo, 

 Botrytis, 3Iorchella, Tuber, Mueor. The number of species is 

 estimated at over 4,000. There are upwards of 700 British 

 species. 



Properties and Uses. — Fungi have very variable properties. 

 Some are medicinal, others edible, and numerous species are more 

 or less poisonous. Many deaths have occurred from poisonous 

 fungi having been mistaken for edible ones, and, apart from their 

 botanical characters, science as yet affords no certain characters 

 by which they may be distinguished ; some general characters, 

 however, will enable us in most cases to do so : these may be 

 tabulated as follows : — 



Edible Mushrooms. 



1 . Grow solitary in dry airy places. 



2. Generally white or "broA^Tiish. 



3. Have a compact brittle flesh. 



4. Do not change colour when cut by the action of the air. 



5. Juice watery. 



fi. Odour agreeable. 



7. Taste not bitter, acrid, salt, or astringent. 



Poisonous Mushrooms. 



1. Grow in clusters, in woods, and dark damp places. 



2. XTsuaUy with bright colours. 



3. Flesh tough, soft, and watery. 



4. Acquii-e a brown, green, or blue tint, wi|en cut and exposed to the air. 



