on the Light emitted from various Bodies. 163 



The water used in general for the experiments, was pure 

 spring water, drawn up from under ground by means of a 

 pump ; and it was always employed cold, unless otherwise ex- 

 pressed. 



SECTION I. 



The Quantity of Light emitted by putrescent Animal Substances, 

 is not in Proportion to the Degree of Putrefaction in such 

 Substances, as is commonly supposed; but, on the contrary, the 

 greater the Putrescence, the less is the Quantity of Light emitted. 



EXPERIMENTS. 



Exper. 1. Two very fresh herrings were bought in the 

 morning, and hung up in the laboratory ; on examining them 

 in the evening, they were beginning to be luminous. 



Exper. 2. Three herrings, which were quite fresh, after being 

 scaled and gutted, were hung up by a string in the laboratory,, 

 The next evening they were become exceedingly luminous in 

 every part, and much lucid matter had exuded, as it were, upon 

 their surface, which was easily scraped off by the blunt edge of a 

 knife ; it also adhered to the fingers, or other parts of the body, 

 when touched ; but, as they grew more putrescent, the quantity 

 of light diminished, and at last was extinguished. 



Exper. 3. A single herring, that was perfectly sweet, was 

 hung up in the laboratory. On the second night, it was co- 

 vered with light ; on the third, not so lucid ; on the fourth, less 

 so ; and so on, in proportion to the degree of putrescence. 



Exper. 4,. Two herrings, somewhat stale, were hung up in 

 the morning, and at 8 P. M. one of them was pretty lumi- 

 nous, but the other less so. On the next evening, the former 



Y 2 



