20 THE ZOOLOGIST. 



that they contrast it with the enormous waste in all industrial 

 methods of producing light. This waste in candle, lamp, or 

 even gas-illumination generally exceeds ninety-nine parts in 

 one hundred. It is least in sources of high temperature, like 

 the incandescent light and electric arc, yet it amounts to the 

 larger part. The authors, in view of this remarkable light 

 without heat of the animals just considered, are of opinion that 

 there is yet hope of obtaining an enormously greater result than 

 we now do in the production of light. 



