ANIMAL AND VEGETABLE PHOSPHORI. 127 



solutions of Epom and other salts, and found that in slight solu. 

 tioiis it shone brighter : hut that in strong solutions it became 

 apparently extinguished, though it again revived by mixing more 

 wa:er. mi. I ri'dui'ing the solution to its j r >per debility ; and thus 

 by alternate!* adding fresh salt, and new supplies of water, he has 

 sometimes revived the same light after ten extinctions. Great cold 

 and heat are also found to extinguish it ; yet a moderate heat ren. 

 ders it more brilliant : it begins to be extinguished at 96 j and 

 when the thermometer is raised to 100 it can be no more revived. 

 It is however capable of being revived, after being frozen by frigo. 

 ritic mixtures. 



It is therefore an anomalous fact, that the light of dead glow, 

 worms continues to augment in heated water, increased to 114 

 degrees. 



Luminous appearance of the Sea. 



FROM what has already been observed, this beautiful and brif. 

 iiant phenomenon is not difficult to be accounted for in most cases : 

 for the vast mass of the ocean contains in itself whatever has the 

 greatest tendency to the production of such a phenomenon. It is 

 the natural province of the greater number of those animals that 

 secrete light from peculiar organs with which they are endowed for 

 this purpose, of phloades, nereids, medusas, ami luminous can. 

 cers ; it holds in its immense bosom, at all times, an enormous 

 quantity of that kind of animal matter, (marine fishes) which is 

 most disposed to throw forth its latent light, in an aggregate and 

 visible form, during its first progress of decomposition ; and unites 

 the different circumstances which chiefly favour such an evolution ; 

 such, for instance, as a fluid menstruum, temperate warmth, and 

 a solution of muriat of soda or common salt. 



If then we see occasionally, in vegetable matter undergoing a 

 slow decomposition, as in rotten wood, a certain portion of light 

 poured forth in a visible form ; if we see it issuing in a still greater 

 degree from bones and shells that have undergone the process of 

 calcination ; if we see it still more freely at times, and under 

 circumstances, thrown forth from the animal exuvia of church, 

 yards, and adhering to the surface of the spot from which it issues, 

 in like manner as the light scraped off from the scales of pieces of 

 putrescent fishes, immersed in salt water, adheres to the knife or 

 the fingers that are employed for this purpose ; how much more 

 easily may we expect to see it thrown forth, and in how much 



