466 History of Luminescence 



2) Why did the splendor gleam in the meat of lamb rather than in 

 other meat? 



3) Why did those shining rays stream forth from the fatty and mem- 

 branous parts rather than from the fleshy or lean ones? 



4) Why did the ensuing corruption extinguish those little fires com- 

 completely, which is different from the way it happens in other 

 decaying things? For it is well known that they acquire light by 

 putrefaction, e. g. putrefying wood and other things. Finally, if 

 those are right who say that light differs from fire merely by the 

 looseness of its parts, how is it that there are many luminous 

 things which are not deemed to be warm, while others again have 

 much warmth but do not show any splendor? 



Those things puzzle me most, and just this shining light shows our 

 mind immersed in deepest darkness and betrays not so much itself as 

 our own darkness. I ask you, illustrious man, that you should pierce 

 with your beacon through that deep darkness which envelops my 

 mind. . . . 



Puerarius replied that he might have something to say even though 

 the book of Thomas Bartholin " which I have avidly read, [is] a 

 perfect work, without fail worthy of its subject which he seems to 

 have exhausted." 



The answer to the first question was: 



Light is a substance and corporeal; it does not actually differ from the 

 celestial or elementary fire. It moves, rebounds, is reflected from bodies 

 that hinder its transit, destroyed by those that do not permit free transit 

 at all, and when its parts come together and unite it turns into that 

 intensity of warmth which properly is called fire. Then it even becomes 

 inflamed and burns. Therefore, light differs from fire only by the loose- 

 ness of its parts, light gathered together becomes fire. . . . 



Puerarius held that Archimedes had proved it just as boys prove 

 it in their play with mirrors in his day. He drew the same conclu- 

 sion as Bartholin, that light is inborn in all bodies. 



Since light differs from fire only by the looseness of its parts, and since 

 the celestial light differs from the elementary one only in its purity, it 

 follows with necessity that the rare fire which enters into the composi- 

 tion of mixed bodies is light. Even if we do not always see it or touch it, 

 light is there within the minute spaces, for example, sparks elicited from 

 stones, which were not seen before, and the inanimate metals, minerals, 

 and stones of which Bartholin wrote. Living creatures contain more of 

 it, even some of the most lowly creatures, e. g. cicindela [the glow-worm]. 



In regard to the second question, why light appeared in lamb 

 meat rather than other kinds, Puerarius discarded one idea, that 



