500 History of Luminescence 



In the same year, C. G. and T. F. L. Nees von Esenbeck, J. J. 

 Noggerath and K. C. G. Bischoff (1823) published a 110-page paper 

 on " Die unterirdische rhizomorphen, ein leuchtender Lebenspro- 

 cess," which included a consideration of all plant phosphorescent 

 phenomena. The authors stated definitely that the light of wood 

 came from Rhizomorpha subterranea stellata, and from R. aidela. 

 These forms did not light in a vacuum or in irrespirable gases but 

 did luminesce under water and in the air. The light was not depen- 

 dent on previous insolation, but was a visible indication of the life 

 process, which required absorption of oxygen, a mild burning. The 

 important point in the work of these men is their recognition that 

 wood luminescence comes from a living thing rather than from a 

 process of chemical decomposition. Attention was also called to the 

 views of Freyesleben in 1796 by Noggerath and C. G. Nees von 

 Esenbeck (1825). 



The ideas of Derschau, Nees von Esenbeck, and others were not 

 immediately accepted. J. von Schmitz (1843) made a special study 

 of the growth of Rhizomorpha, both in the forest and in the labora- 

 tory under different conditions, and was impressed with the close 

 connection between the life of the plant and its luminescence. This 

 circumstance led Schmitz to the belief that perhaps the light of 

 luminous wood, a non-living material, was a different sort of lumi- 

 nescence from that of Rhizomorpha after all. He also observed that 

 different samples of Rhizomorpha varied greatly in the intensity of 

 their light, depending on internal conditions. 



L. R. Tulasne (1848) studied not only Rhizomorpha subterranea 

 and a mushroom, Agaricus olearius, but also the phosphorescence 

 of dead leaves, which Naudin had described in 1846. He empha- 

 sized the fact that the light appeared not only during life, as in 

 Agaricus and Rhizomorpha, but also after death, for example in 

 the case of wood, dead leaves, the pulp of fruit, such as the peaches 

 about to decay (J. A. Deslonchamps, 1836) and other organized 

 material. The listing of these luminescences together was a good 

 sign, but Tulasne's remarks about light after death indicate he did 

 not fully appreciate the significance of the observation of Derschau. 

 Final proof of the fungus origin of the light of luminous wood came 

 with the publication of Heller's (1853) paper, described in a later 

 section. T. Hartig (1855), not knowing of Heller's work, was 

 another who thought the light had nothing to do with a fungus, 

 although he saw fungal fibers in the wood.^° In the meantime, more 

 attention was directed to luminous mushrooms, whose light was 



^° R, Hartig (1873) later discovered the relation of rhizomorphs to Armillaria. 



