LICHENALES. 



679 



wise been of benefit in causing the expulsion of clots, hydatids, &c. ; nor has 

 it been without use in restraining uterine haemorrhage, whether puerperal or 

 non-puerperal. 



It has also been employed in amenorrhoea, leucorrhoea, gonorrhoea, &c., 

 and many cases have been published in corroboration of its remedial proper- 

 ties in these diseases. Of late years it has attracted much attention for its 

 anti-hemorrhagic virtues, and numerous instances are given where it has 

 been eminently beneficial as a styptic. A full account of its various applica- 

 tions will be found in Dunglison's New Remedies, 265, and Pereira's Ele- 

 ments of Materia Medica, ii. 71. 



It is administered in a variety of forms : in powder, in doses of about a 

 scruple every twenty minutes, till its effects are produced, or till about a 

 drachm is given ; in infusion, made with a drachm of Ergot to four fluid 

 ounces of water, one-third to be given at a time, and repeated, as above. 

 Where it is administered for other purposes than promoting contractions of 

 the uterus, the doses to be smaller. A tincture is sometimes given in fluid 

 drachm doses. The oil is effective in from 20 to 50 drops. 



Group LVI. — Lichenales. 



Perennial plants, spreading over the surface of the earth, rocks, trees, &c, in dry 

 places, in the form of a lobed and foliaceous, or hard and crustaceous or leprous sub- 

 stance, called a thallus. This thallus is composed of two layers, a cortical and a medul- 

 lary; the former merely cellular, the latter cellular and filamentous. Reproductive 

 matter of two kinds : 1st. Sporules naked, or lying in membranous tubes (theca), and 

 immersed in small disks called shields; 2d. Of separated cellules of the medullary layer, 

 of a green colour, and called gonidia. 



They are found in all parts of the world, but their principal abode is in 

 temperate regions. Lichens have two distinct classes of characters : one 

 making them nutritive, and medicinally useful ; the other rendering them ex- 

 cellent dyes, after they have undergone certain preparations. They are said 

 to contain several peculiar principles, as Cetrarine, Stictine, Varioline, &c. ; 

 but their nutritive properties are owing to an amylaceous substance, more 

 analogous to gelatine than to starch ; this has received the name of Li- 

 chenine. 



Among the alimentary and medicinal species, the best known are the fol- 

 lowing. 



Fig. 331. Fig. 332. 



C. islandica. 



Gyrophorac. 



