Curiosities of Science. 35 



that the iris of an eel showed itself susceptible of the excite- 

 ment sixteen days after the eyes were removed from the creature's 

 head. So far as is yet known, this muscle is the only one on 

 which light thus takes effect. Phil. Trans. 1857. 



LIGHT NIGHTS. 



It is not possible, as well-attested facts prove, perfectly to 

 explain the operations at work in the much-contested upper 

 boundaries of our atmosphere. The extraordinary lightness of 

 whole nights in the year 1831, during which small print might 

 be read at midnight in the latitudes of Italy and the north of 

 Germany, is a fact directly at variance with all that we know, 

 according to the most recent and acute researches on the cre- 

 puscular theory and the height of the atmosphere. Biot. 



PHOSPHORESCENCE OF PLANTS. 



Mr. Hunt recounts these striking instances. The leaves of 

 the cenothera macrocarpa are said to exhibit phosphoric light 

 when the air is highly charged with electricity. The agarics 

 of the olive-grounds of Montpelier too have been observed to be 

 luminous at night ; but they are said to exhibit no light, even 

 in darkness, during the day. The subterranean passages of the 

 coal-mines near Dresden are illuminated by the phosphores- 

 cent light of the rkizomorpha pkosp/wreus, a peculiar fungus. 

 On the leaves of the Pindoba palm grows a species of agaric 

 which is exceedingly luminous at night; and many varieties 

 of the lichens, creeping along the roofs of caverns, lend to them 

 an air of enchantment by the soft and clear light which they 

 diffuse. In a small cave near Penryn, a luminous moss is 

 abundant; it is also found in the mines of Hesse. According 

 to Heinzmann, the rhizomorpha subterranea and aidulce are also 

 phosphorescent. See Poetry of /Science. 



PHOSPHORESCENCE OF THE SEA, 



By microscopic examination of the myriads of minute insects 

 which cause this phenomenon, no other fact has been elicited 

 than that they contain a fluid which, when squeezed out, leaves 

 a train of light upon the surface of the water. The creatures 

 appear almost invariably on the eve of some change of weather, 

 which would lead us to suppose that their luminous phenomena 

 must be connected with electrical excitation ; and of this Mr. C. 

 Peach of Fowey has furnished the most satisfactory proofs yet 

 obtained.* 



LIGHT FROM THE JUICE OF A PLANT. 



In Brazil has been observed a plant, conjectured to be an 



* See Things not generally Known, p. 88. 



