JDEAD ANIMAL MATTER. 103 



remarked that the quantity of light produced in 

 phosphorescent putrefactions diminishes as the 

 process of putrefaction itself advances. 



Cold prevents the phenomenon of phosphores- 

 cence in dead fish, but only temporarily, for the 

 light bursts forth again with its usual intensity as 

 soon as the temperature becomes milder. It has 

 been also seen that this phosphorescence is ac- 

 companied by no production of heat in the parts 

 which shine. We have already noticed this fact 

 in the mineral and in the vegetable world, and we 

 shall notice it again when speaking of luminous 

 animals. Boiling water and high temperatures 

 destroy the phosphorescence which occupies us 

 here. 



I have myself proved the exactness of most of 

 the above facts whilst studying the body of a dead 

 stockfish (Ray a) in a luminous condition. In a 

 short note published in the ' Comptes-Rendus' of 

 the Paris Academy of Sciences for I860, I have 

 shown by direct chemical experiment that no phos- 

 phorus can be found in the luminous grease which 

 shines upon fish. I was at first inclined to attri- 

 bute their phosphorescence to the presence of 

 some microscopic fungi, but at present I am more 

 inclined to believe it is owing to some peculiar 

 organic matter which possesses the property of 

 shining in the dark like phosphorus itself. 



The bodies of other marine animals shine after 



