6 EDIBLE BRITISH MOLLUSCA. 



Co.sta, 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 Moutius. 

 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 Pliolas 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/^ 



Pholas clactylus, 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. 



t < Phosphorescence,' by T. L. Phipson, Ph.D., F.C.S., p. 105. 



% Ibid. p. 104. 



