112 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



widely distributed in nature, and which constitutes the phos- 

 phorescent matter of animals, living or dead. This is not 

 only the cause of the phosphorescence of dead fish and dead 

 animal matter, but it is secreted by certain luminous worms 

 (the scolopendra, etc), and probably by all animals which 

 shine in the dark, and frequently by certain living plants 

 (Agaricus, JSuphorbia, etc.). It is also developed by the de- 

 composition of vegetable matters, under certain conditions 

 (fermentation of potatoes, etc.). 



At the ordinary temperature noctilucine is an almost liq- 

 uid, nitrogenized matter. It mixes with water, but does 

 not dissolve in it, and appears to have a density little less 

 than this liquid. It is white, and, whether extracted from a 

 living or dead animal, is luminous, and possesses an odor re- 

 sembling that of caprylic acid. It is insoluble in alcohol 

 and ether, and is dissolved and easily decomposed by the 

 mineral acids and alkalies. When fermented in contact witli 

 water, it disengages an odor of cheese. When fresh it is 

 strongly phosphorescent, the production of light being due 

 to its oxidation in contact with moist air. Indeed, it will 

 shine as well in water as in air. It is a little more brilliant 

 in oxygen gas ; and it has been observed that it is always 

 most lustrous when the wind blows from the southwest 

 that is to say, when there is most ozone in the air. As soon 

 as the oxidation of all the matter is accomplished the produc- 

 tion of light ceases. If the slightest quantity of air adheres 

 to it, it shines for some moments in moist carbonic acid. 



In phosphorescent animals noctilucine is supplied from a 

 special organ as the bile is secreted by the liver and ap- 

 pears to be employed to produce light almost as soon as it 

 is formed. It is also produced in certain conditions of tem- 

 perature and moisture by dead animal matter of various 

 kinds ; but whatever its source, it always gives the same 

 kind of light that is to say, one that is almost monochro- 

 matic, giving a spectrum principally visible between the lines 

 E and F, and possessing the same uniform chemical proper- 

 ties, as far as has been observed. It is secreted in a state 

 of considerable purity by the Scolopendra electrica, and, by 

 causing several of these myriapods to run about on a large 

 capsule of glass, enough can be obtained to allow an exami- 

 nation of its principal properties. 



