82 History of Luminescence 



be but put into a clear Crystal glass, so that the air may freely come at 

 them, with a little grass, they may perchance give light for the space of 

 some 12 dayes, if every day fresh grass be put to them; but at the length 

 as they languish and faint away, so the light by little and little is remitted 

 and slackned, and in the end they dying (as before is said) it is totally 

 extinguished. 



Perpetual Lamps 



The idea of a liquor liquidus prepared from fireflies is possibly 

 the outgrowth of one of the unfulfilled goals of the alchemists, a 

 perpetual lamp.®° Such lamps ''^ were mentioned in prose and poetry 

 and widely believed in during the fifteenth and sixteenth centuries. 

 The ancients were said to have the secret of such lamps, used in 

 tombs, and that they burned until someone opened the tomb and 

 let in the air, when they went out. Fortunio Liceti (1577-1657) 

 published a whole book on the subject, De Lucernis Antiquorum 

 Reconditis (Venice, 1621; Utini, 1652). 



As late as 1684, Robert Plot (1640-1689) published ^^ A Dis- 

 course Concerning the Sepulchral Lamps of the Ancients, showing 

 the possibility of their being made divers Waies. His paper is of 

 interest because he invoked luminescence as a possible source of the 

 light. One of the " waies " was a " weik " of asbestos (" linum asbes- 

 tinum, earth flax or salamander's wooll ") and crude petroleum 

 (" naphta or liquid bitumen ") , but Plot also suggested that phos- 

 phorus might have been used in a way he had observed during 

 experiments of his " worthy Friend, Frederick Slare, M. D." All 

 sepulchral lamps were not described as going out when a tomb was 

 opened, and Plot consequently thought the lamps might not be 

 " inkindled " in the tomb but begin to light when exposed to the 

 air, just as phosphorus in an evacuated glass phial glows when the 

 air is let in. Phosphorus was regarded as such a miraculous sub- 

 stance in the late seventeenth century that Plot's explanation may 

 have seemed plausible at that time. 



Shining wood is another possibility. A light in any tomb or 

 grave constructed of wooden parts might come from luminous fungi 



Cardan (Exotericarum exercitationum, 194) he wrote: " If you use the cicindelae as 

 an example that a liquid can be artifically devised and prepared that shines in the 

 dark, it seems you can impose the light that has been brought down from heaven info 

 matter, like a captive rower into a trireme, and hold it in chains." 



*" The perpetual fires of the temple of Attush Kudda, near Baku on the Caspian 

 Sea, were undoubtedly due to the abundant petroleum of this region. Petroleum or 

 natural gas were fuels for many " eternal fires." 



"^ See B. H. Carrington, Legends of sepulchral and perpetual lamps. Monthly 

 (Quarterly) Journal of Science 1: 715-123, 1879. 



«2R. Plot, Phil. Trans. 14:806-811, 1684. 



