OBSERVATIONS ON SPONTANEOUS LIGHT. JJ 



VII. 



A Continuation of the Experitnents and Obfervations on the Light 

 which is fpontaneoujly emitted from, various Bodies * ; with 

 Jbme Experiments and Obfervations onfolar Light, when im- 

 bibed by Canton's Phofphorus. By Nathaniel Hulme, 

 M. D. F. R. S. and A. S. 



SECTION XI. 



Tfte Ejects of various aerial Fluids onfpontaneous Light. 

 INTRODUCTION. 



JL HE apparatus employed for experiments with any kind of Apparatus mate 

 air, unlefs otherwife exprefled, confcfted of the following ufe of » 

 parts : . I . A tea-faucer, holding about three ounces of water. 

 2. A wide-mouthed phial, which would contain about ten 

 ounces of liquid. 3. A fmall wooden fland, compofedofa 

 flender pillar or pin, nearly four inches high, fixed into a 

 round bafe, a little more than an inch in diameter, and half 

 an inch thick. This fland was fattened by flrong thread to 

 the middle of a piece of flat lead, fuch as lines Chinefe tea- 

 chefls, having holes in it to admit the thread; the lead was 

 about three inches fquare, and doubled, to give it weight and 

 liability. The top of the pillar was made pointed ; and a 

 round piece of cork, about an inch in diameter, and half an 

 inch thick, was fixed upon it, by means of a fuperficial hole 

 bored in its under part with a gimlet. 



When the whole apparatus was put in ufe, the phial was and its ufe. 

 filled with cold pump water, in a pneumatic tub, then in- 

 verted, and the fpecies of air to be employed was let up into 

 it, to the quantity of about eight ounces. The fubjeci for ex- 

 periment being applied to, or faftened upon, the top of the 

 cork, the fland was placed on the tea-faucer, and then intro- 

 duced, under water, into the phial containing the air. The 

 whole apparatus, being now fupported by the tea-faucer, 



* Phil. Tranf. 1801. p. 483. The former part is in the Phil. 

 Tranf. for .1800, page 1 61, and alfo in the Philof. Journal, Quarto, 

 IV. 421, 451, 



with 



