140 PHOSPHORESCENCE. 



In tropical countries, where the action of the sun 

 is more powerful during the day, and longer sus- 

 pended during the night than with us, and where 

 consequently hoth growth and decomposition go 

 on much more rapidly, those airy meteors of the 

 night are much more common than they are with 

 us. They are more common at sea too than they 

 are on land ; though there they seldom rise above 

 the surface unless the water is agitated. But when 

 that is done, in certain states of the weather, 

 namely, after long calms, when the water has 

 not been much disturbed, there is a ripple of light 

 at the bows of the vessel, and her wake bears some 

 resemblance to the tail of a comet. Every splash 

 of the oars flings radiance, and a hand skilfully 

 dipped in the water appears to be kindling. There 

 seems little reason to doubt that all those lights 

 are produced by decomposition, whether of the 

 ultimate destruction of dead animals or of the 

 separation of waste in living ones ; and that they 

 are nothing more than some of the highly inflam- 

 mable gaseous compounds kindled by the friction 

 of motion. That they do exist in living animals 

 is seen in the various species of fire-flies which in 

 some parts of the tropical countries make the even- 

 ing sky as brilliant as if the whole heavens were 

 hung with countless myriads of little lamps, and 

 all those lamps were dancing in mazes of incessant 

 motion. We have no luminous flying insect in this 

 country ; but the female glow-worm, which is not 

 uncommon under hedges in the warmer places of 

 England, and at the warm season of the year, emits 

 a beautiful bluish white light, which appears much 

 brighter in consequence of the dark and shady 

 places in which it is seen. The male of the glow- 



