The Eighteenth Century 191 



Watch here below, if phosphor-light be shed: 

 It is the Soul, the winged Psyche is it; 

 Pluck off the wings, 't is but a hideous worm: 



This description of the soul is no doubt a reflection of the old 

 custom of representing the spiritual aspect of hiunan beings as lumi- 

 nous, departing at death from the body, which is left a repugnant 

 thing. 



It is perhaps fitting to conclude the eighteenth century by men- 

 tion of one writer who did do justice to various phosphors. He was 

 the English physician, scientist, and poet, Erasmus Darwin (1731- 

 1802) , giandfather of Charles Darwin. His published scientific ob- 

 servations on luminescence were slight, but he managed to include 

 a surprising number of references to this subject and to scientific 

 phenomena in general in his poem. The Botanic Gardan, first pub- 

 lished in 1791. Part II of the poem, " The Loves of the Plants," 

 which had appeared anonomously in 1789, contains the following: 



So shines the glow-fly, when the sun retires. 

 And gems the night-air with phosphoric fires; 

 Thus o'er the marsh aerial lights betray. 

 And charm the unwary wanderer from his way. 



In Part I, " The Economy of Vegetables," Darwin referred to the 

 northern lights which: 



Dart from the North on pale electric streams. 

 Fringing Night's sable robe with transient beams. 



Then he spoke of the faint lights seen after the stin sets, personi- 

 fied as nymphs, " Effulgent Maids," which: 



O'er Eve's pale forms diffuse phosphoric light. 

 And deck with lambent flames the shrine of Night. 

 So, warm'd and kindled by meridian skies. 

 And view'd in darkness with dilated eyes, 

 Bologna's chalks with faint ignition blaze, 

 Beccari's shells emit prismatic rays. . . . 

 Or mark with shining letters Kunkel's name 

 In the pale Phosphor's self-consuming flame. 



The ignis fatuus, believed to come from " inflammable air " near 

 the surface of a morass, the " flashing " of Calendula flowers, at first 

 thought to be a luminescent phenomenon, the glowworm, and other 

 animal lights were ascribed to these same Nymphs: 



You with light Gas the lamps nocturnal feed, 

 Which dance and glimmer o'er the marshy mead; 

 Shine round Calendula at twilight hours, 



