On the Light from crgdnifed Bodies. 4^^ 



SECTION I. 



Tht ^lafrtity of Light emitted by putrefcent Animal Suhjlances, is not in Proportion to the 'De- 

 gree of PutrefaBion in fuch Subflancesy as is commonly fuppofed ; but, on' the Cotttrary, the 

 greater the Putrefcence, the lefs is the ^tantity of Light emitted, 



EXPERIMENTS. 



Exper. I . Two very frefh herrings were bought in the ihofriingi and hung up in thfe 

 laboratory ; on examining them in the evening, they were beginning to be luminous. 



Exper. 2. Three herrings, which were quite frefli, after being foaled and gutted, were 

 hung up by a ftring 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 

 ■furface, which was eafily fcraped off by the blunt edge of a knife ; it alfo adhered to the 

 fingers, or other parts of the body, when touched ; but, as they grew more putrefcent, 

 the quantity of light diminiflied, and at laft was extinguiflied. 



Exper. 3. A fingle herring, that was perfedly fweet, was hung up irt the laboratory. 

 On the fecond night, it was covered with light ; on the third, not fo lucid ; on the fourth, 

 lefs fo ; and fo on, in proportion to the degree of putrefcence. 



Expert i^ Two herrinsrs, fomewhat dale, were hung up in the morning, and at 8 P. M. 

 one of them was pretty luminous, but the other lefs fo. On the next evening, the former 

 ■was but flightly luminous, and the latter was dark; on the fucceeding evening, they were 

 both dark. 



Exper. 5. Two mackerels were brought from the market at i P. M. which, to the fight 

 and fmell, were perfectly fweet and good. Being then carried into the dark laboratory, 

 and examined, the one was found to be a little luminous, and the other pretty muchfo 

 efpecially about its belly. 



Exper. 6. A fine frefli mackerel, with a bright eye, was purchafed about noon, and 

 placed as ufual in the laboratory, the temperature of which, at that time, was about 54°. 

 At 1 1 P. M. this beautiful fifli was luminous about the head and upper parts; and the 

 infide of the mouth, which was wide open, flione with moft brilliant light. The next 

 evening, the whole body of the fifli was very luminous : on the third night, it was lefs fo j 

 and on the fourth the light was nearly extinguiflied. 



Exper, 7. In the forenoon, about ten o'oclock, a couple of fine-looking mackerels were 

 hung up in the laboratory, at the temperature of 56°, and at 10 P. M. they began to 

 fhine in various parts, the light feeming to proceed from within outwards. On the fecond 

 night, they put on a luminous appearance all over their furface: on the third,^the light 

 was not fo vivid; and on the fifth it was almoft extindt. 



N. B. In experiments of this kind, for the production of light, the fiflies Ihould 

 always be gutted, the roes taken out, and the fcales, if any, carefully removed. As the 

 loea are likewife very produftive of light, ihey ihoiUd be prefervcd. 



OBSER- 



