Experiments on the ^ociWiicsi m\\\av\s. 413 



smallest scintillation after the acklition of the aether. On sub- 

 stituting chloroform, however, in the second experiment in 

 the place of the aether, a very bright and persistent phospho- 

 rescence was given out for the space of a few minutes, after 

 which the water speedily became dark, the animalculae being 

 evidently killed. Before taking leave of this division of the 

 subject, it may be as well to notice the influence simply of 

 fresh water upon the Noctilucae. On pouring some of the 

 sea-water, rendered luminous by the presence of these little 

 animals, into a vessel already containing some fresh rain-water, 

 a subdued continuous glow was given out from several lumi- 

 nous points for a short period, during which the specks of 

 light were seen to subside to the bottom of the vessel, and 

 very speedily afterwards to become totally extinguished. 



Of the foregoing experiments, those connected with the em- 

 ployment of the gases appear to be the most interesting; and 

 any degree of importance they may possess will be best ap- 

 preciated from their bearing upon the topics now to be brought 

 under notice, in the form of a few concluding remarks of a 

 general character on the 



Phceiiomena of Vital Phosphorescence. — The development of 

 light as the result of a vital function, and as constituting an 

 essential feature in the oeconomy of some forms of animal life, 

 is a phaenomenon of so interesting and remarkable a nature, 

 that it could not fail to arrest the attention of naturalists and 

 philosophers in almost every age. It is, however, only since 

 the impulse which the cultivation of chemical science received 

 about the latter part of the last century, that the subject has 

 come to be investigated in the true spirit of scientific inquiry. 

 It was about the period here alluded to, also, that the animal- 

 cular source of the phosphorescence of the sea was first in- 

 disputably established; and some valuable papers appeared 

 on the subject in the excellent journal conducted by Mr. 

 Tilloch. At this time, however, no higher object appears to 

 have been sought, than the mere establishment of the fact, as 

 just stated, of the dependence of the phosphorescence of the 

 sea upon an animalcular origin. Many individual instances 

 of phosphorescent marine animals were, indeed, adduced in 

 support of the new doctrine ; but this was done without much 

 method or accuracy of detail; and the minuteness and trans- 

 parency of the little animal which forms the subject of the pre- 

 sent notice appear to have occasioned its being at that time 

 overlooked. 



At a period, then, when the fact of the animalcular source of 

 marine phosphorescence was barely admitted, and may be said 

 to have been almost a question still subjudice, it was scarcely 



