454 0" the Light from organijcd Bodies. 



SECTION VII. 



Spontaneous Light is not accompanied nvith any Degree of fettftble Heat, to be difcovered by * 



Thermometer. 



EXPERIMENTS. 



Exper. u A luminous herring, and another that was quite frefli and not luminous, 

 were placed for a confiderable time in the fame degree of temperature. A thermometer 

 was then applied to each of them, but no difference of heat could be difcovered. 



Exper. 2. The foft roe of a herring, in an exceedingly lucid ftate, and a thermometer, 

 were kept together for fome time in the laboratory. The roe was then put upon the bulb 

 of the thermometer, without affedling it. 



Exper. 3. A mackerel, which (hone with very brilliant light, was alfo put to the teft of 

 a thermometer, but the inftrument remained ftationary. 



Exper. 4. The bulb of a thermometer was furrounded by many fmall pieces of fliining 

 wood, uncommonly luminous, which were kept in that fituation for fomc timej but 

 the light made no alteration upon the thermometer. 



Exper. 5. Illuminated liquids, and fpring water, being kept together in the laboratory, 

 always preferved tlie fame degree of temperature. 



SECTION VIII. 



The EffeEls of Cold on fpontaneous Light. 



EXPERIMENTS. 



The Light of Fi/hes. 



Exper. I. Five fmall gallipots, containing three pieces of foft-roe of herring, and two of 

 the herring itfelf, all very luminous, were placed in a frigorific mixture, compofed of fnow 

 and fea-falt ; and, in about an hour and a half, the light was quite extindl, and the bodies 

 totally frozen. The gallipots were then removed into a vcflel of cold water, that their 

 contents might be gradually thawed ; which being done, they all recovered their priftine 

 luminous ftatc. The pieces were afterwards obfervcd to (hine during three fucceeding 

 nights. 



Exper. 2. A fmall phial, containing three or four drams of liquid impregnated with 

 light, was placed in a frigorific mixture. As the liquid froze, its lucidnefs gradually 

 dimlnllhed; and, when it was quite congealed, the light perfeAly difappeared. The 

 phial was then taken out, and put into cold water, at about 49" temperature, that the ice 

 might be gradually liquefied ; and, when that was accompliftied, the whole fluid became 

 as luminous as before. 



4 The 



