34 



OBSERVATIONS ON SPONTANEOUS LIGHT, 



oxigen gas ex 

 hibited no 

 difference of 

 illumination. 



§ 2. 



The Effects of oxigen Gas or vital Air* onfpontaneous Light. 



EXPERIMENTS. 



FiA, ihining Experiment I. A piece of frefh herring, of about three drams 



^if?« r n ^' weight, was introduced above water, into eight ounces of 

 worms in com- o * * o 



mon air and in oxigen gas. On the fecond night it was obferved to be faintly 

 luminous; on the third, the quantity of light was increafed; 

 on the fourth, it continued nearly in the fame flate ; and on 

 the fifth the light was diminifhed. 



Exp. 2. A piece of very frefh mackerel, of the fame mag- 

 nitude, was alfo put above water. On the fubfequent even- 

 ing it was pretty lucid, and continued the fame on the night 

 following. 



Exp. 3. At 9 P. M. a cork, finely illuminated with mac- 

 kerel-light, was introduced above water : it continued very 

 lucid at eleven. On tke next evening it was dark. 



Exp. 4. Another cork, rendered luminous with the fame 

 kind of light, was put above water at 10 P. M, The next 

 morning, at fix o'clock, only a glimmer of light was perceived 

 and at 10 P. M. it was extinft. 



Exp. 5. At 9 P. M. a fragment of mining wood was in- 

 troduced above water ; it was obferved to be frill very lumi- 

 nous at eleven ; but the light was not quite fo vivid, nor (o 

 extended in breadth, as when the wood was put in. On the 

 fucceeding night, at eight o'clock, it remained faintly lucid. 



Exp. 6, A little after 8 P. M. another fragment of wood, 

 fhining very brightly, was introduced above water, into the 

 fame air that was ufed in the laft experiment : it continued 

 very luminous at eleven; but the light was diminifhed in 

 quantity. On the next evening it was found to be extinguifhed. 



Exp. 7. The fame air was employed again at 8 P. M. with 

 a pretty large and thick fragment of wood, uncommonly lucid : 

 its light continued vivid and broad at half an hour paft eleven. 

 The following night, at eight o'clock, the light was ftill fome- 

 what extenfive and bright. 



Exp. 8. In three other experiments with fliining wood, in 



frefh oxigen gas, the light was totally extinguifhed in the fpace 



of twenty-four hours. 



* The oxigen gas made ufe of was obtained from manganefe, by 

 means of heat 

 2 Experiments 



