to some American species of Lampyris. 119 



for two or three minutes, then flashes three or four times, 

 each flash being much longer than usual, and after each 

 flash it does not resume its previous opacity, when the 

 powers of life become weak, but before death its bril- 

 liancy remains stationary, with a kind of creeping scin- 

 tillation. 



When it is taken out of the spirit apparently dead, it 

 is opake, but on a slight touch with a metallic substance, 

 and a harder touch with any thing, it shines bright, and 

 gradually dies away after half a minute or longer : but 

 it may be excited to flash six or seven times ; perhaps 

 oftener. 



In a perfect Torricellean vacuum, it shines a short time, 

 and then becomes opake. No irritation will now cause 

 it to give out light, but on the admission of the least 

 bubble of air, it shines again. 



When it is compressed between the mercury and the 

 the tube halfway up the column, it emits light frequently, 

 for a short time, but very faintly. After remaining in 

 vacuo for an hour, or perhaps longer, its powers of light 

 are found to be but little diminished, on being again 

 brought into the atmosphere : very little, indeed, consi- 

 dering the violence done by its introduction. * * * * 



In hydrogen gas, the lampyris emits but one or two 

 feeble flashes, and soon dies. 



In carbonic acid gas, nearly the same effects are ob- 

 served. 



