8o4 THE POPULAR SCIENCE MONTHLY. 



VEGETABLE PHOSPHORESCENCE. 



Bt ELLEN PEESCOTT. 



THERE is a curious myth which gives to Castor and Polkix, twin 

 sons of Zeus, a divine control over the phosphorescence of air and 

 ocean. Being present by invitation at the marriage of two youths of 

 Amyclffi with the daughters of Leucippus, they became enamored of 

 the brides and with the doubtful courtesy of the period attempted to 

 carry them off. In the ensuing struggle Castor was slain ; but Pollux, 

 with a boundless and heroic love that bridged the " abyss 'twixt life 

 and death," besought their father Zeus to restore him, proposing that 

 to meet the ends of justice they should each live only on alternate 

 days. This he granted, and, " kindling stars upon their brows, set 

 them for ever with the immortals." 



A religious idea was therefore involved in the superstition of the 

 ancient mariner that the pale phosphoric light, or " St. Elmo's fire," 

 which occasionally appears upon the masts of ships, in an electrical 

 condition of the air, denoted the. presence of these divinities as they 

 rode upon the storm-clouds through the heavens. This indicates a 

 recognition of the phenomena of phosphorescence in a remote antiqui- 

 ty ; but, in advancing from the philosophy of myths and symbols to 

 an era of empirical knowledge, there was necessarily a jjeriod of con- 

 fusion, when old fancies TV^ere replaced by new facts which had not 

 accommodated themselves to the novelty of the position. Even when, 

 through the onward roll of centuries, the wisdom of the ancients had 

 shrunken into grotesque fables, a long period intervened which pro- 

 duced no marked scientific results. 



Throughout the seventeenth century inquiry was directed to the 

 phenomena of solar light and the light of incandescent bodies ; but, 

 while phosphorescence was everywhere observed, no explanation on 

 scientific principles was attempted, until in 1675 Nicolas Lemery, in a 

 paper on the preparation of solar phosphorus, stated that the light 

 produced was the result of rapid molecular motion ; thus accepting 

 the doctrine foreshadowed by Huygens and Euler, in opposition to the 

 emission or corpuscular theory of Newton. These prophetic utter- 

 ances, however, of the present undulatory theory of light were not 

 recognized ; it was reserved for later experiment to demonstrate the 

 truth of this intuitive perception. 



The "persistence of force" and the "indestructibility of matter" 

 must first be proved, before it could be shown that the phenomena of 

 phosphorescence are due to the same causes as the light evolved by 

 electrical discharge, chemical combination, or mechanical movement. 

 If, as Dr. Young has shown, light be motion or vibration of a luminif- 

 crous ether which fills space and permeates all bodies, the conditions 



