in the different Kinds of Gas, and in Fb/ids. 91 



bright light, and even at the end of twenty-four hours I 

 could observe no decrease of anv consequence. 



The remaining gas, when subjected to examination by 

 means of Fontana's eudiometer, in which I mixed it with 

 the same quantity of nitrous gas, showed a decrease of 30 

 dcffrees. A taper immersed in this gas was immediately 

 extinguished. Phosphorus evaporated strongly in it, and it 

 rendered lime water prettv turbid, without a considerable 

 quantity of the gas being absorbed. 



Experiment. II. 



T filled a bell glass with oxygen gas prepared from oxide 

 of manganese well washed with milk of lime. The wood 

 immersed in it did not emit a stronger light than in atmo- 

 spheric air or water. At the end of forty-eight hours the 

 light seemed to decrease a little, and on the sixth day it 

 was about a third weaker. The pliosphorescence afterwards 

 slowly decreased ; on the 14th day it ceased entirely, and 

 was not afterwards revived in the open air. The volume 

 of the gas decreased very little, scarcely 0*2. Having put 

 another piece of wood into the remaining gas, it continued 

 lo emit light without being weakened. 



On trvmg the gas which remained in an eudiometer, it 

 showed onlv a decrease of 21 degrees; and in about 15 se- 

 conds, when the red vapour of the nitrous acid had disap- 

 peared, I observed a faint whitish vapour from the gas float- 

 ing over the water. For the sake of comparison i tried a 

 portion of the same oxygen gas in a similar bell closed in 

 the same manner with \\ater, but in which no wood had 

 been immersed, and found that in the same eudiometer it 

 showed a diminution of 266 degrees. Artificial phosphorus, 

 when placed in the remaining gas, became luminous and 

 evaporated. A taper immersed in it was innncdiately ex- 

 tinguished : it was not inflammable, had no considerable 

 smell of mouldiness, and rendered lime water turbid ; but 

 it was not absorbed by it in any considerable degree. 



Having repeated this experiment several times, I obtained 

 sin)ilar results, or results very little ditlerent. The phos- 

 phorescence of the wood, however, decreased once on the 

 fourth day, and ceased totally on the seventh ; though the 

 gas, when subjected to proof, showed a diminution of from 

 faO to 120 degrees. This diflerence may have arisen chiefly 

 from a diflerence in the nature of the wood; for it is not 

 possible to obtain two pieces exactly the same in every re- 

 spect. On the wood which had emitted light in oxvgen gas 

 1 observed no mouldiness, nor any perceptible alteration. 

 B 3 ' It 



