94 OBSERVATIONS ON SOME MOLLUSCA AND ZOOPHYTES. 



as we have never seen them. Fishes may be distinctly seen 

 swimming about when the sea is luminous ; and it even seems 

 that they contribute to give it that appearance; but if ex- 

 amined when at rest, it is easy to convince oneself that the 

 power of emitting light is not inherent in them ; and that 

 the effect produced by them in this case is the same that may 

 be obtained by agitating any inanimate substance in the sea." 



Our authors then proceed to detail some experiments re- 

 lative to these phosphorescent phenomena, the results of 

 which may be thus stated. 



Diluted sulphuric acid, gently added to sea- water, con- 

 taining the phosphorescent animalculae, excited a sudden bril- 

 liancy, arising from distinct globules of light, which gradu- 

 ally faded into darkness. A fresh dose of the acid caused a 

 re-appearance of the light : but a third repetition of the ex- 

 periment produced no effect ; the animalculae were destroyed, 

 and the phosphorescence could not by any means be repro- 

 duced. When undiluted sulphuric acid was added to the 

 water, the animalculae suddenly perished, emitting a slight 

 luminosity. Vinegar and muriatic acid produced the same 

 effect, — the latter especially with much greater force. 



" What is the true cause of this phosphorescence ? Which 

 is the organ that in the more simple mollusca, as well as the 

 more complicated, serves to impress upon our view such 

 effects ? These are questions that, perhaps, will never be 

 answered with certainty. We shall confine ourselves to 

 making a single remark on this subject, which is, that in 

 studying these animals, and handling great numbers of them, 

 our sense of smell has always experienced the same sensation 

 as that produced by a great quantity of electricity collected 

 in the plate of an electrical machine. 



" The observation with which we shall conclude this chap- 

 ter, is the most remarkable fact of this kind which we have 

 yet beheld. 



" Having anchored under the small island of Rawak, situ- 

 ated exactly under the Equator, we one evening saw lines of 

 a dazzling whiteness on the water. Crossing them in our 

 canoe, we wished to take up some portion, but we found no- 

 thing but water, whose light disappeared in our hands. Soon 

 afterwards, during the night, and while the sea was calm, we 

 saw several of these white steady lines near the ship. Upon 

 examination we discovered that they were caused by some 

 very small zoophytes ; and that these possessed a principle 

 of phosphorescence so subtle, and so capable of expansion, 

 that when they swam swiftly, and in a zigzag direction, they 

 left glittering trains on the sea about an inch wide, which 



