50 ^^ LUMINOUS ANIMALS. 



I wished next to try the influence of electricity on th« 

 luminous property of animals, 

 but not when Exp» 10. A medusa heniispherica was placed in a small 

 eectnie , g^agg dish, containing a quantity of water, merely suffici- 

 ent to allow the animal to preserve its fii^ure; being insu- 

 lated, it was electrified, and sparks drawn from it, which 

 hud not the slightest effect ; the experiment was repeated 

 several times with different individuals, but without ex- 

 citing the animals to throw out light, 

 iinlosswhen Exp» 11. Some hemispherical medusae were placed in 

 w^re pafsccf contttct with the two ends of an intt rruj)ted chain, and 

 through them, slight electric shocks passed through them. During the 

 very moment of their receiving the shock no light was visible, 

 bat immediately after the medusae shone like illuminated 

 -wheelS), which appearance remained for «ome seconds. 



• Upon the closest inspection with a magnifying glass, no 

 contractile motion could be perceived to accompany the 

 exhibition of the light. The application of electricity in 



; this instance seems to have acted merely as a strong me- 



• chanic shock. 



; The above experiments on tiie luminous medusae were 

 made at Heme, with the assistance oF George May, Esq., 

 , / of Stroudbouse, and in the presence of a large company, 



capable of accurately distinguishing their results, 

 Generaldedttc- ' it seems proved by the foregoing experiments, that, so 

 lions from far from the luminous substance being of a phosphorescent 

 «ent5*'^^^"' nature, it sometimes shows the strongest and most constant 

 light, when excluded from oxigen gas; that it in no cir- 

 cumstances undergoes any process like cojnbustion, but is 

 actually incapable of being inflamed ; that the increase of 

 lieat, during the shining of glow-worms, is an accompani- 

 foent, an<l not an effect of tlje pneuomenon, and depends 

 upon the excited state of tlse iiisect; and lastly, that heat 

 and electricity increase the exhibition of light, merely by 

 - operating like other stimuli vi[^on the vital properties of the 

 animal. 

 Tile JieUt not ' 1" confirmation of these opinions, I may quote the high 

 affected bj ar>3t,jn,t^j<)fjty of jhe secretary of the society, who has found, 

 icmd of ja«. ^j^^^^ the light of the glow-worm is not rendered more 

 brilliant ill oNJgeo, or in oxigenated muriatic gus, than in 

 '- • coiumou 



