474 History of Luminescence 



John Beal 



About the time of Boyle's work on shining wood and shining 

 flesh, John Beal or Beale (1603-1683) made some observations on 

 luminous fish and actually examined the luminous material with a 

 microscope. Beal, a doctor of theology and Rector at Yeavel in 

 Somersetshire, published his observations in the first volume of 

 the Philosophical Transactions under the title " An Experiment 

 to Examine what Figure and Celerity of Motion begetteth, or 

 encreaseth Light and Flame " (p. 226-228) . Beal actually published 

 before Boyle. He described how, on May 5, 1665, " fresh Mackrels 

 were boyl'd in Water, with salt and sweet herbs " and left for pickle. 

 On the evening of May 8 the cook 



found the water at first motion ^^ [had] become very luminous, and the 

 Fish shining through the water, as adding much to the Light, which 

 the water yielded. 



Wherever the drops of this water (after it was stirr'd) fell on the 

 ground, or benches, they shin'd: And the children took drops in their 

 hands, as broad as a penny, running with them about the house, and 

 each drop, both neer and at distance, seem'd by their shining as broad 

 as a six pence, or a shilling or broader. . . . 



Beal noted that no light came from the lower side of the fish, 

 but " from the throat and such places as seemed a little broken in 

 the boyling." 



I took a piece that shin'd most, and fitted it, as well as I could devise 

 in the night, both to my great Microscope, and afterwards to my little 

 one; but I could discern no light by any of these Glasses; nor from any 

 drops of the shining water, when put into the Glasses. And May 10. in 

 the brightst rays of the Sun, I examin'd, in my great Microscope, a small 

 broken piece of the Fish, which shin'd most the night before. We could 

 find nothing on the surface of the Fish very remarkable. It seem'd 

 whitish, and in a manner dried, with deep inequalities. And others, as 

 well as myself, thought, we saw a steam, rather darkish, than luminous, 

 arising, like a very small dust, from the fish: And rarely here and there, 

 a very small, and almost imperceptible sparkle in the Fish. Yet of these 

 sparkles we are certain, we numbered them, and agreed in the number, 

 order and place. Of the steam I am not confident, but do suspect our 

 Eyes in the bright Sun, or that it might be some dust in the Aire. 



It is hardly possible that the " dust " could have been luminous 

 bacteria. 



^® Motion of the water resulted in the appearance of light because more oxygen 

 dissolved, but Beal, and also later writers (Hulme, 1800) , were not in a position to 

 realize this. 



