162 Dr. Hulme's Experiments and Observations 



As instances of the first may be mentioned, the shell-fish called 

 Pbolas, the Medusa phosphorea, and various other Mollusca. 



When deprived of life, marine fishes in general seem to 

 abound with this kind of light. The honourable Mr. Boyle 

 commonly obtained light, for his use, from the whiting, as 

 appears from many parts of his works : the author of these 

 experiments and observations procured his fish light chiefly from 

 the herring and the mackerel. 



The flesh of quadrupeds has also been observed to emit light. 

 Instances of this are mentioned by Fabricius ab Aquapendente ; 

 by T. Bartholin; by Mr. Boyle; and by Dr. Beale ; for 

 which, see T. Bartholin, de Luce Animalium, p. 183; Boyle's 

 Works, Vol. III. p. 304; Phil. Trans. Vol. XI. p. 599. 



In the class of insects are many which emit light very copi- 

 ously, particularly several species of Fulgora or Lantern-fly, 

 and of Lampyris or Glow-worm; also the Scolopendra electrica; 

 and a species of crab, called Cancer fulgens. 



Rotten wood is well known to emit light spontaneously. Peat 

 earth also has the same property. Of the effects of the latter, a 

 remarkable instance is related in Plot's Natural History of Staf- 

 fordshire, p. 1 15. 



The place where the following experiments were made, was 

 a dark wine-vault, which, for distinction's sake, the author calls 

 the laboratory. The heat of this laboratory varied, throughout 

 the year, from about 40 degrees of temperature to 64 . The 

 thermometer made use of was that of Fahrenheit. 



The weight is always to be supposed that called Troy weight. 

 The liquid measure employed, was that used for wine in this 

 country : the ounce containing 8 drams Avoirdupois ; and the 

 pint, 16 ounces. 



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