192 PHOSPHORESCENCE. 



It is well known that when a platinum wire is 

 suspended, after being heated, in a mixture of 

 ether- vapour and air, or in a mixture of alcholic 

 vapour and air, it continues incandescent for 

 hours together, until all the ether or alcohol em- 

 ployed is spent. In this case, the spirituous 

 vapour is burnt by the oxygen of the air; but 

 neither the oxygen nor the ether become lumi- 

 nous, it is the wire alone which gives out light. 

 This curious phenomenon may go far, perhaps, 

 to explain the phosphorescence of dead animal 

 matter. The whole circumstances connected with 

 it have been brought forward in my prize memoir, 

 *'La Force Catalytique, ou Etude sur les Pheno- 

 menes de Contact/ printed at Harlem in 1858 

 (see Appendix) . 



As regards phosphorescence in the vegetable 

 kingdom, possessing, as we do, only a few isolated 

 observations, we are devoid of sufficient experi- 

 mental data to offer any theoretical consideration 

 as to its production. If the light emitted by 

 flowers appears to be electrical, that evolved from 

 fungi is more probably connected with chemical 

 action. 



In luminous animals, we find everything pre- 

 pared by nature for the production of light; 

 namely, a phosphorescent organ specially adapted 

 for this purpose. 



Taken in its most satisfactory point of view, the 



