544 History of Luminescence 



most segments. Sometimes the light appears continuous but is often 

 rhythmic like the heartbeat, but the rhythmic light ceases and becomes 

 continuous when one cuts off the last segment . . . there arises in the 

 previously mentioned fluid rounded vesicles, which luminesce from the 

 deeper layers and at times disappear. . . . During the lighting, the quiver 

 of these small vesicles can be easily observed. The fluid lights outside 

 the body but without rhythmic lighting . . . and lights as long as it 

 remains fluid. In water, vinegar and alcohol the sap retains its light, 

 indeed luminesces longer and with more intensity than in the air. 



Another Italian interested in fireflies as bearing on fire and light 

 was Domenico Bottoni (1641-1731) in whose Pyrologia Typo- 

 graphica (Naples, 1692) some eight pages are devoted to the insect. 

 An accompanying plate (reproduced as fig. 13) shows a large male 

 firefly in a flask on a table, near pens and an open book, to imply 

 that enough light is emitted for reading and for writing. Bottoni's 

 views have already been discussed in Chapter IV. 



SYNCHRONOUS FLASHING 



One of the extraordinary sights in the tropics of the Far East is 

 synchronous flashing of fireflies, in which great numbers of these 

 insects turn their light on and off at the same moment. This phe- 

 nomenon appears to have been first recorded ^° by Englebrecht 

 Kaempfer (1651-1716), a German botanist and traveler, who visited 

 southeast Asia between 1683 and 1693. In his book on Japan and 

 Siam, translated and published by Sir Hans Sloane in 1727, Kaemp- 

 fer wrote of the fireflies in the Meinam River near Bangkok, Siam: 



The glow-worms (Cicindelae) represent another shew, which settle on 

 some Trees, like a fiery cloud, with this surprising circumstance, that a 

 whole swarm of these Insects, having taken possession of one Tree, and 

 spread themselves over its branches, sometimes hide their Light all at 

 once, and a moment after make it appear again with the utmost regu- 

 larity and exactness, as if they were in perpetual Systole and Diastole. 



Somewhat later, in 1771, the Civil and Natural History of the 

 Kingdom of Siam, was published by Francois Rene Turpin, who 

 gave the following description: " Nothing can afford a finer sight 

 in the night time than to see a tree entirely covered with fire flies: 

 It seems decked with bright sparks, which expire and rekindle almost 

 at the same instant. These flies are not hurtful. It is easily per- 



^" The Jesuit, P^re Guy Tachard, visited Siam in 1685 and wrote of the " mouches 

 luisantes " on " trees along the river near Bancok " with their " infinit^e de lumi^res " 

 reflected in the water, but did not mention synchronous flashing {Voyages de Siam, 

 etc., 150. 1689) . 



