OBSERVATIONS ON SPONTANEOUS LIGHT. 33 



however, be improper to obferve, that the illumination of the 

 cork did not always continue fo long as twenty-four hours ; for 

 it muft, ofcourfe, vary according to the quantity of luminous 

 matter applied, and its degree of brilliancy. 



Exp. 7. A large piece of rotten wood was received from Rotten wood, 

 the country, which fhone only in one place. The luminous 

 portion was fawed off for ufe, and the dark part left in the 

 laboratory. On going into the laboratory, the fecond night 

 after this operation, I was furprifed to fee the dark piece, 

 which had been left there, very lucid in feveral places where 

 fmall fplinters had been broken off in fawing ; many mining 

 fragments alfo lay fcattered on the floor. 



Exp. 8. A quantity of rotten wood, moderately mining, 

 was blown upon for fome time with a pair of bellows ; but I 

 could not perceive that this had any effect on the light, fo as 

 to render it more vivid. 



Exp. 9. A fmall piece of mining wood was tied upon one 

 of the corks of the apparatus, and introduced above water, 

 where it continued lucid until the fifth night. In another ex- 

 periment, the light was extinguifhed on the fourth night ; and 

 and in a third much fooner. 



Exp. 10. A living glow-worm, in a fhining fiate, was Glow-worm, 

 fubmitted to the action of a pair of bellows ; but the con- Thefe are not 

 tinuance of the blafl did not apparently increafe its glowing excited b y bcl - 

 quality. 



Exp. 1 1 . A very luminous dead glow-worm was fixed upon 

 a cork of the apparatus, by means of a fmall pin, and then put 

 into the phial, above water. It continued to thine as vividly 

 as it did when in the open air, forming a pure white light, of 

 a circular ftiape. 



OBSERVATIONS. 



Obfervation. 1 . Thefe experiments prove, that objects which 

 abound with fpontaneous light in a latent ftate, fuch as the 

 herring, mackerel, and the like, do not emit it when deprived 

 of life, except from fuch parts as have been fome time in con- 

 tact with the air. 



Obf. 2. They likewife (how, that the blaft of a pair of bel- 

 lows does not increafe this fpecies of light, as it does that 

 which proceeds from combuftion. 



Vol II. —May, 1802. P The 



