38 OBSERVATIONS ON SPONTANEOUS LIGHT. 



§ * 



The Effe&s of hidrogen Gas or inflammable Air* on fpontaneow 

 Light. 



EXPERIMENTS. 



Hidrogen ga* Experiment I . At 9 P. M. a piece of frefh herring, weighing 



^heVroduaion about three drams > was introduced above water, into hidrogen 



of light. gas. It was retained therein three days and three nights, 



without emitting any light. It was then taken out, and expofed 



to the action of atmofpherical air. On the following night it 



was found to be luminous ; but was dark again on the next 



night. 



Exp. 2. Another piece of frefli herring was put above 

 water, at 6 P. M. This was alfo kept in the gas the fame 

 length of time, without producing any light. It was then ex- 

 pofed to the open air, and infpecled two fucceffive nights, but 

 it remained dark. 



Exp. 3. The fame experiment was then made with a piece 

 of mackerel, which was taken out on the fourth night, without 

 producing any fhining appearance. The next evening, it 

 emitted a very faint light, which did not continue twenty-four 

 hours, 

 but extinguifhes Exp. 4. A cork, brilliantly illuminated with mackerel-light, 

 it. (Fiih) was introduced above water ; and the light was extinguished 



in about the fpace of an hour. 



Exp. 5. At 39 minutes part 9 P. M. another luminous cork 

 was put above water ; it loft fome of its light pretty foon, but 

 was not extinct at twelve. 



Exp. 6. A cork, with herring-light, was introduced above 

 water, at 23 minutes pad 6 P. M. The light gradually dimi- 

 nifhed, and was only faintly vifible at eleven. 



Exp. 7. A fragment of very fhining wood was put above 

 water, at 9 P. M. and was dark at eleven. 

 Common air Exp. 8. Another fragment was put above water, at 40 mi- 



again revives it. nutes pa ft 8 p # m. at 50 tne light was much diminithed, and 

 at 8 minutes pafl 9 the fhining ceafed. The wood was then 

 taken out, and expofed to the open air, when the light revived 

 in a very beautiful manner. 



* This gas was obtained from zinc and diluted fulphuric acid; 



Exp. 



