6 EDIBLE BRITISH MOLLUSCA. 



Costa, as quoted by Dr. J. G. Jeffreys in his ' British 

 Conchology/ says that it is so phosphorescent, that if 

 the flesh is chewed and kept in the mouth, the breath 

 becomes luminous and looks like a real flame. 



Dr. Coldstream states that "the phosphorescent 

 light of this mollusk is given out most strongly by the 

 internal surfaces of the respiratory tubes, and that it 

 is strongest in summer; and Professor John Miiller 

 has observed, that when Pholades are placed in a 

 vacuum, the light disappears, but reappears on the 

 admission of air ; also, that when dried, they recover 

 their luminous property on being rubbed or moistened.* 



Many others have also made experiments with the 

 Pholas, and have studied its phosphorescence, viz,, 

 Reaumur, Beccaria, Marsilius, Galeatus, and Montius. 

 The two first mentioned endeavoured to render this 

 "luminosity permanent, and the best result was ob- 

 tained by placing the dead mollusk in honey, by which 

 its property of emitting light lasted more than a year. 

 Whenever it was plunged into warm water, the body 

 of the Phola* gave as much light as ever/'f 



Beccaria also found that a single Pholas " rendered 

 seven ounces of milk so luminous that the faces of 

 persons might be distinguished by it, and it looked as 

 if transparent." J 



Pholas dadylus, or the long oyster, as it is called at 

 Weymouth, is not often eaten in England, but is 

 generally used for bait. A Newhaven fisherman, how- 

 ever, told me they sometimes collect some for eating 

 from the chalk boulders, between Newhaven and 



* Forbes and Hanly, vol. i. p. 107. 



f ' Phosphorescence/ by T. L. Phipson, Ph.D., F.C.S., p. 105. 



I Ibid. p. 104. 



