LICHEN ISLANDICUS. 
181 
phthisis, and other disorders of the Inngs, it must be admitted to 
afford the same good effects that can be obtained from other demul- 
cents, and the mucilages. Iceland Lichen however must not be 
regarded as a demulcent only, for owing to the bitter principle it 
contains, its tonic powers are not inconsiderable ; and lo the combi- 
nation of these properties, its good effects in phthisis are to be 
attributed. Dr. Crichton informs us that, from what he has seen, 
he is fully convinced there are only two species of this disease where 
Lichen promises a cure, viz. phthisis hsemoptoica, and phthisis 
pituitosa, or mucosa. In several of these, he says, " I have seen 
the patients so far get the better of their complaints as to be dis- 
missed cured ; but whether they remained long so or not, I cannot 
take upon me to say." Lichen has certainly considerable effects in 
allaying tickling cough ; it also relieves the breathing when op 
pressed, and involves the acrid matters contained in the stomach 
and bowels, which are often the cause of diarrhoea; it renders the 
animal fluids more bland, by which it tends to mitigate hectic fever ; 
and at the same time, its tonic powers invigorate the digestive 
organs. This Lichen is also useful in debility after acute diseases, 
and in emaciations, particularly those arising from the great dis- 
charge of ulcers ; and also in diarrhoea, dysentery, the sequelae of 
measles, hooping cough, &c. It has been used (in decoction) as an 
enema in haemorrhoids, and as an injection in gonorrhoea. That 
this Lichen strengthens the digestive powers, and proves extremely 
nutritious, there can be no doubt; hence it has been recommended 
to be taken in considerable quantities as an article of diet ; but 
when used as a dietetic article, it requires to be deprived of its 
hitter principle, which may be done by infusing it for a short time in 
boiling water, after which it is to be boiled in a fresh quantity of 
water or milk, ia the proportion of one or two ounces of Lichen to 
one quart of water or milk. Of this, a tea-cupful may be drank 
frequently in the course of the day. This is the only form in which 
Lichen is prescribed. 
Off. Lichen, or Iceland Liver-wort. 
Off. Pp. Decoctum Lichenis, L, D. 
VOL. 
II. 
