Shining Fish, Flesh, and Wood 485 



morpha fragilis " given as a synonym. Accompanying the figure was 

 Sowerby's description: 



Found in a wine cellar in Little St. Helens, London, creeping among 

 saw-dust and bottles in the autumn of 1796, communicated by Mr. B. M. 

 Forster. It is remarkable for being luminous in the dark, when fresh, 

 at the ends of the shoots. Mr. Forster has doubted whether this phos- 

 phoric appearance may not be owing to some vinous moisture imbibed, 

 rather than a natural property of the fungus. 



The ^vork of R. Hartig (1873) proved that these growths were 

 the mycelium of a common fungus, Armillaria mellea, whose fruit- 

 ing body is nonluminous. According to A. von Humboldt ^^ (1799) , 

 Freyesleben, a counselor of mines, was the first to observe lumines- 

 cence of rhizomorphs, which he called Lichen filamentosus, in mines 

 at Freiburg in 1796. The terms Lichen pinnatus and Dematium 

 violaceum were also used at that time for luminous rhizomorphs 

 (Heller, 1853: 83) . Von Humboldt was unable to separate any- 

 thing which remained Imninous from the wood which he studied. 

 It was only with the observations of Derschau in 1823 that rhizo- 

 morphs and luminous wood became associated. 



Luminous Potatoes, Roots, Leaves, Fruit, and Cheese 



Wood is not the only vegetable material which may become phos- 

 phorescent. A most interesting and famous case of luminous pota- 

 toes occurred in the military barracks of Strassburg on January 7, 

 1790. The circumstance was recorded by Valmont de Bomare in 

 the Journal de Physique for 1790 (36: 225) as a letter from " M. 

 d'H— Officier d'Alsace, sur un phenomene phosphorique." The 

 account was widely quoted in German and English publications 

 and was exaggerated to include a statement that the officer on guard 

 thought the barracks were on fire. 



Actually the officer was astonished when he entered the barracks 

 to perceive a great light at an hotir when lights were prohibited by 

 the police. It seems that the soldiers had started to prepare potato 

 soup but discovered that fermentation connected with germination 

 had begun, and, after they were cut, the potatoes were discarded in 

 a pail. As darkness fell they were seen to give off a light like glow- 

 ing charcoal by which it was possible to read the characters of print. 

 Next morning the officer examined the yellowish potato slices. They 

 contained little starch and were covered with a multitude of tiny 



^* A. von Humboldt, Versuche iiber die chemisch Zerlegung der Luftkreises, IX, 

 t)ber die Entbinding des Lichtes, 231, 1799. 



