in t fie different Kinds of Gas, and in Fhiids. 147' 



ttierit was made at the teinperature of from 8 to 12° of 

 Reaumur, the same as in common air. The phospho- 

 I'escence did not become Weaker till the end of several hours, 

 and in twentv-four hours it completely ceased. It could, 

 however, be in part revived by wrapping up the pieces of 

 wood in filtering paper; but when the water had the tem- 

 perature of 45° the light was speedily extinguished^ and 

 could not be again revived. 



Experiment XX. 



Having introduced wood strongly phosphorescent into 

 julphurous acid, nitrous acid, and muriatic acid, the light 

 either instantaneously ceased altogether, or in one or twa 

 minutes, and could not be again revived in any manner. 



Experiment XXI. 



I added a considerable quantity of water to Xhd above; acids, 

 in such a manner that only a few drops of acid were put 

 into a cubic inch of water. The light of the rotten wood 

 decreased in three minutes, ceased in general in from six to 

 ten minutes, and was not a^ain visible when the wood waS 

 wa.shed with water in the armosphcric air. 



Experiment XXII. 



Rotten wood appeared phosphorescent in nmriate of am-' 

 monia, nitrate of potash, common salt, and tartaric acid j 

 and e\cn somewhat stronger in the second and third solution 

 than in atmospheric air. The light continued longer than 

 in common spring water. 



Experiment XXIII. 



The phosphorescence of rotten wood continued in a di- 

 lute solution of carbonate of potash as well as in liquid am- 

 monia two (jr three minutes, and then became entu'ely ex- 

 tinct. In linseed oil the wood appeared phosphorescent 

 without any diminution eighteen hours, and in thirty was 

 entirely extinguished. 



Experiment XXIV^ 



I immersed fihosphoresccnt wood in spirit of wine, and 

 found that it was extinguished in from four to eight minutes. 

 In sulphuric ether the hght strongly decreased after twenty 

 minutes, and in a short time entirely disappeared. It could 

 not be again revived by the common mode of treatment. 



If these experiments, which I was not able to carry any 

 further for wautof phosphorescent wood, be couipiu'od wjtti 



K2 the 



