. VIII. EFFECTS OF OXYGEN. 159 



twenty-four hours the insects no longer shone, though the 

 detached segments were still feebly luminous. The air 

 which remained under the glasses was analyzed thirty- 

 six hours after ; and it was found that the oxygen had 

 entirely disappeared, and was replaced by an equal volume 

 of carbonic acid. In 11*8 'cubic centim. of atmospheric 

 air, wherein the entire insects had been put, we found 2-4 

 cubic centim. of carbonic acid. In the glass which con- 

 tained the luminous sections, all the oxygen had not been 

 absorbed. 



Effect of Chlorine. The entire insects remained lively 

 and glowing in chlorine, quite as long as the separated 

 segments ; but when life and phosphorescence had disap- 

 peared, they were neither restored by introducing air or 

 oxygen, nor by applying heat. The insects, and their 

 segments even, when crushed, no longer evinced phospho- 

 rescence. 



Glow-worms which have been left for twenty -four hours 

 in atmospheric air contained in a bell-glass, became slightly 

 luminous for a few moments when they were warmed by a 

 lamp. 



Effects of Oxygen. I put some living and glowing worms 

 into some bell-glasses filled with oxygen gas over mercury; 

 they lived for about forty hours, and during the whole time 

 continued to glow. 



I placed ten luminous segments, taken from ten living 

 glow-worms, in pure oxygen. The segments continued to 

 be phosphorescent for four whole days, and we saw them 

 luminous, even during the day, when we looked at them in 

 a dark place. The gas left in the glass was one-third car- 

 bonic acid, and two-thirds oxygen. 



I put some other luminous segments into this oxygen, 

 after having deprived it of the carbonic acid by means of 

 potash, and again observed the same result. The seg- 



