on the Light emitted from various Bodies 405 
Exper. 4. At 9 P. M. a piece of fresh herring, of about three 
drams in weight, was introduced above water, into about eight 
ounces of atmospherical air. On the second night it was be- 
come luminous ; on the third and fourth, it continued shining ; 
and on the fifth the light was extinguished. This experiment 
was frequently repeated, with both the flesh of herring and 
of mackerel, and nearly with the same result. 
Exper. 5. The cork of the apparatus was well smeared with 
the luminous matter of a mackerel, and then introduced above 
water. It continued to shine finely all that evening ; and the 
light was not quite extinct on the succeeding night. 
Exper. 6. Another cork was illuminated with herring-light, 
at half an hour past six F. M. and introduced above water. It 
remained very bright at eleven ; and retained a glimmering light 
the next evening. The two last experiments were often repeated, 
and, in general, with similar effects. It may not, however, be 
improper to observe, that the illumination of the cork did not 
always continue so long as twenty-four hours; for it must, 
of course, vary according to the quantity of luminous matter 
applied, and its degree of brilliancy. 
Exper. 7. A large piece of rotten wood was received from the 
country, which shone only in one place. The luminous portion 
was sawed off for use, and the dark part left in the laboratory. 
On going into the laboratory, the second night after this opera- 
tion, I was surprised to see the dark piece, which had been left 
there, very lucid in several places where small splinters had 
been broken off in sawing ; many shining fragments also lay 
scattered on the floor. 
Exper . 8. A quantity of rotten wood, moderately shining, 
