VEGETABLE LAMPS. 139 



erto been successful with any other species than the ordinary 

 mushroom. Attempts were made in France to cultivate 

 truffles, at first apparently with considerable promise, but 

 ultimately without much satisfaction. There is no good 

 reason to suppose it impossible or improbable that many 

 species might be devoted to experiments in that direction. 

 Some species of Polyporus have been employed as styptics, 

 or beaten till soft and used as amadou. One species in 

 Burmah has a good reputation as an anthelmintic. Some 

 species of Polysaccum and Geaster are employed medicinally 

 in China. Species of Elaphomyces were at one time sup- 

 posed to possess great virtues now deemed apocryphal. 

 Ergot, developed on rye, wheat, and the gerraen of various 

 grasses, still maintains its position in the pharmacopoeia ; but 

 is almost the only fungus now employed, and that sparingly, 

 by the legitimate medical practitioner. 



In the Cardiff coal-mines an interesting plant is found, 

 which emits so brilliant a light, that the men have been 

 able to "see their hands by it," and was visible at a distance 

 of sixty feet. Mr. Worthington Smith, who is anthority for 

 this, observed the same phenomenon in Polyporus sulfureus. 



While various theories have been recorded as to the phys- 

 iological cause of the light in cryptogams, and many writers 

 give the most careful details of the structure of the luminous 

 parts, we are unable to go a step farther to explain the cause 

 of the. light which appears to be a combustion, but does not 

 consume. 



