52 OBSERVATIONS ON SPONTANEOUS Mfirft* 



with water in it, was depofited in the laboratory for experi* 

 ments on liglit. By this contrivance, the experiments were 

 made in about eight ounces of air, by meafure, confined above 

 two ounces of water. 



5 i. 



The Effects of common or atmofpherical Air on fpontaneous Light > 



EXPERIMENTS. 



Thf cxdufion Experiment \ . Two frefli herrings were hung up together 



of armofpheric ; n the laboratory, fo as to touch each other at their flat fides ; 



appearance of anc * ** was obfcrved that the parts in contact remained dark, 



ipontaneous while thofe expofed to the open air became very luminous. 



*' s Exp. 2. Another frefh herring was laid upon a piece of thick 



Y\(h. brown paper, and placed in the laboratory. On examination, 



the next evening, the upper part, which was expofed to the 



air, was very lucid ; but the underfide, lying upon the paper, 



remained quite dark. 



Exp. 3. A luminous herring was divided tranfverfely quite 

 through its middle flefhy part; but the inlide was perfectly- 

 dark. On the following night, that which before was dark 

 had become luminous. 



Exp. 4. At 9 P. M. apiece of frefh herring, of about three 

 drams in weight, was introduced above water, into about 

 eight ounces of atmofpherical air. On the fecond night it was 

 become luminous ; on the third and fourth, it continued 

 fhining ; and on the fifth the light was extinguifhed. This ex- 

 periment was frequently repeated, with both the fleih of 

 herring and of mackerel, and nearly with the fame refult. 



Exp. 5. The cork of the apparatus was well fmeared with 

 the luminous matter of a mackerel, and then introduced above 

 water. It continued to fhine finely all that evening ; and the 

 light was not quite extinct on the fucceeding night, 



Exp. 6. Another cork yvas illuminated with herring-light, 

 at half an hour paft fix P.M. and introduced above water. 

 It remained very bright at eleven ; and retained a glimmering 

 light the next evening. The two Iaft experiments were often 

 repeated, and, in general, with fimilar effects. It may not, 



however, 



