LICHENS AS MEDICINE 409 



directions for its preparation as a cure for chest complaints. The doctrine 

 of "signatures" influenced practitioners in its favour, but it contains lichenin 

 which acts as an emolHent. In England, it was taken up by the famous 

 Dr Culpepper^ who, however, believed in astrology even more than in sig- 

 natures. He says : " it is of great use with many physicians to help the 

 diseases of the lungs and for coughs, wheesings and shortness of breath 

 which it cureth both in man and beast." He adds that " Jupiter seems to 

 own the herb." A century later we find Dr John Hill 2, who was a physician 

 as well as a naturalist, stating that the great tree lung-wort has been at all 

 times famous in diseases of the breast and lungs, but by that time "it was 

 not much used owing to change in fashions." 



The only lichen that has stood the test of time and experience as a real 

 remedy is Cetraria islandica, and even the " Iceland moss '' is now rarely 

 prescribed. The first mention in literature of this famous plant occurs in 

 Cordus^ as the Muscus with crisp leaves. Some years later it figures among 

 the medicinal plants in Sibbald's^ Chronicle of the Scottish Flora, and Ray^ 

 wrote of it about the same time as being known for its curative and ali- 

 mentary properties. It was Linnaeus^ and later Scopoli', who gave it the 

 important place it held so long in medicine. It has been used with advantage 

 in many chronic affections as an emollient and tonic. Cramer" in a lengthy 

 dissertation gathered together the facts pertaining to its use as a food, 

 a medicine and for dyeing, and he gives recipes he had himself prescribed 

 with marked success in many different maladies. It has been said that if 

 "Iceland moss" accomplished all the good it was alleged to do, it was indeed 

 a " Divine gift to man." 



The physiological action of cetrarin (acid principle of the lichen) on 

 living creatures has been studied by Kobert^ and his pupils. It has not any 

 poisonous effect when injected into the blood, nor does it work any harm 

 when taken into the stomach even of small animals, so that it may be safely 

 given to the most delicate patients. Nearly always after small doses peri- 

 staltic movements in the intestines are induced which indicate that as 

 a drug it might be of service in the case of enfeebled organs. In larger 

 doses it may cause collapse in animals, but if administered as free cetraric 

 acid it passes through the stomach unchanged to become slowly and com- 

 pletely dissolved in the intestine. The mucous membrane of the intestine 

 of animals that had been treated with an overdose, was found to be richer 

 in blood so that it seems as if cetrarin might be of service in chlorosis and 

 in assisting digestion. 



Cetrarin has also been proved to be a nerve excitant which might be 

 used with advc.ntage in mental maladies. 



' Culpepper 1652. ^ Hill 1751. ' Cordus 1561. « Sibbald 1684. " Ray 1686. 



* Linnaeus 1737. '' Scopoli 1760. ' Cramer 1880. ' Robert 1895. 



