CHEMISTRY AND TOXICOLOGY OF MUSHROOMS. 295 



purchased by the quart. The nutritive value of one cent's worth of 

 oysters " on the half shell " would be interesting ! 



The question of the toxicology of the higher fungi is one of very 

 great theoretical and practical interest. But on account of the great 

 difficulties in the way of such investigations comparatively little has 

 yet been accomplished. A few toxic compounds belonging chiefly to 

 the class termed alkaloids have, however, been cjefinitely isolated. 



Choline This alkaloid is of wide occurrence in the animal and 

 vegetable kingdoms. It has been isolated from Amanita muscaria, 

 A. pantherina, Boletus luridus, and Helvetia esculenta. It is not very 

 toxic, but on uniting with oxygen it passes over to muscarine. 

 According to Kobert the substance formed from choline on the decay 

 of the mushrooms containing it is not muscarine, but a very closely 

 related alkaloid, neurin. This transformation of a comparatively 

 harmless alkaloid to an extremely deadly one simply by the partial 

 decay of the plant in which the former is normally found, emphasizes 

 very much the wisdom of rejecting for table use all specimens which 

 are not entirely fresh. This advice applies to all kinds of mush- 

 rooms, and to worm-eaten and otherwise injured, as well as decayed 

 ones. Neurin is almost identical in its physiological effects with 

 muscarine, which is described below. 



Muscarine. This is the most important because the most danger- 

 ous alkaloid found in the mushrooms. It is most abundant in Ama- 

 nita muscaria, it is also found in considerable quantity in Amanita 

 pantherina, and to a lesser, but still very dangerous extent in Boletus 

 luridus and Russula emetica. It is quite probably identical with bul- 

 bosine, isolated from Amanita phalloides by Boudier. Muscarine is an 

 extremely violent poison, .003 to .005 of a gram (.06 grain) being a 

 very dangerous dose for a man. Like other constituents of mush- 

 rooms, the amount of muscarine present varies very greatly with 

 varying conditions of soil and climate. This, indeed, may account 

 for the fact that Boletus luridus is regarded as an edible mushroom in 

 certain parts of Europe, the environment being such that little or no 

 muscarine is developed. 



According to Kobert, Amanita muscaria contains, besides choline 

 and muscarine, a third alkaloid, pil:^-atropin. This alkaloid, like 

 ordinary atropin, neutralizes to a greater or less extent the musca- 

 rine. The amount of pilz-atropin present varies, as other constit- 

 uents of mushrooms vary, with varying conditions of soil, climate, 

 etc., and it may be that in those localities where the Amanita 

 muscaria is used for food the conditions are favorable for a large pro- 

 duction of pilz-atropin which neutralizes the muscarine, thus making 



