CHAPTER V 



THE CHEMISTEY OP LIGHT PRODUCTION, PABT I 



Two experiments, both performed very early in the 

 history of Bioluminescence, are of great importance in 

 understanding the nature of animal light Boyle (1667), 

 as already mentioned, proved the necessity of air for the 

 luminescence of wood and fish and Spallanzani (1794) 

 showed that parts of luminous medusae gave no light 

 when dried but if moistened again would emit light as 

 before. We see then, that air (oxygen), water, and some 

 photogenic substance are necessary for the light produc- 

 tion. Spallanzani 's experiment, which has been confirmed 

 for a great many luminous forms, shows also that animal 

 luminescence is not a vital process, in the same sense that 

 the conduction of a nerve impulse is a vital process. A 

 nerve loses its characteristic property of conduction on 

 drying or maceration while luminous cells still possess 

 the power to luminesce after drying or maceration. Using 

 the terminology of the older physiology we may say that 

 ' ' living protoplasm ' ' is not necessary for light production. 



The experiments of Boyle (1626-91) are of great inter- 

 est, especially those in which he studied the behavior of 

 shining wood under the receiver of his air pump. On 

 October 29, 1667, he wrote : 



"Exp. I.: Having procured a Piece of shining Wood, 

 about the bigness of a groat or less, that gave a vivid 

 Light, (for rotten Wood) we put it iato a middle sized 



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