OBSERVATIONS ON SPONTANEOUS LIGHT. 35 



Experiments were made, at the fame time, and in the fame 

 manner, with atmofpherical air and mining wood ; but it was 

 not very evident that the wood (hone more vividly in the latter 

 air than it did in the oxigen gas. 



Exp. 9. A living glow-worm was put into a two-ounce 

 phial, with a glafs ftopple, containing pure oxigen gas, and 

 kept therein for fome time. It was then taken out, and ex- 

 pofed to the open air ; but no difference, either in the brilliancy 

 or the quantity of its light, could be difcovered. 



Exp. 10. A luminous dead glow-worm was then inclofed 

 in about five ounces of the gas j but no increafe of its mining 

 quality could be perceived. 



Exp. 11. At fix o'clock P. M. a fhining dead glow-worm 

 was introduced above water into oxigen gas : it continued 

 very lucid therein at 7 P. M. fliewing a pure white light. It 

 was then taken out, and put above water into atmofpherical 

 air, where it (hone, to all appearance, as fplendidly as it did 

 when it was in the oxigen gas. 



OBSERVATION. 



It appears, from thefe experiments, that oxigen gas does 

 not act upon this kind of light, fo as to render it much more 

 vivid than it is in atmofpherical air ; which is quite contrary 

 to what fome authors have alledged. 



§ 3 



The Effects of azotic Gas onfpontaneous Light, 

 I. Azotic Gas, obtained from lean mufcuhr Flejh and diluted 

 nitric Acid, in a very low Heat, as recommended bj/ M. 4f 

 Fouhcroy. 



EXPERIMENTS. 

 Experiment I . A piece of frefh mackerel, weighing about Azote gas does 

 three drams, was introduced above water, into about eight not admlt of the 



r i • • i • • , • Jr produ&ion of 



ounces of this azotic gas j and it was retained therein five f pon taneous 

 days, without emitting any light. light but 



Exp. 2. About the fame quantity of frefh herring was then ]™e inftaiices* 

 put above water, into the fame gas ufed for the laft experiment, for a time if 

 and remained in it for the fpace of three days, in a dark ftate. ^ e c v j d ° ufiy pr0 * 

 This experiment was repeated, and with a fimilar remit. 



Exp. 3. At 45 minutes paft 7 P. M. a cork, finely illumi- 

 nated with mackerel-light, was put above water into the gas, 

 and it was found pretty luminous at eleven. On the next even- 

 ing, at eight o'clock, it Hill exhibited a faint degree of light. 

 D 2 A fimilar 



