510 History of Luminescence 



was enough light to read the smallest print with ease. It was as if the 

 " Milky Way " as seen through a telescope, " scattered in millions like 

 glittering dust " had dropped down into the ocean, and we were sailing 

 through it. 



Such descriptions could be repeated indefinitely. 



This phosphorescence or " burning " of the sea mystified the early 

 scientists as completely as it fascinated the poets and travelers.* The 

 most superficial inspection would reveal that the larger lights of the 

 sea were dtie to animals like jellyfish, but the apparently uniform 

 brightness when viewed from the deck of a ship gave no hint of the 

 myriads of microscopic organisms responsible for the phenomenon. 



Early explanations of the light of the sea quite naturally stressed 

 the connection with motion. As indicated in Chapter IV, Francis 

 Bacon (1605) grouped together the " dashing of sea water on a dark 

 night " and " the fervent froath of the sea " with other apparently 

 luminous phenomena like the sweat of heated horses and the glow^ 

 of animal eyes. He wrote: ^ " Sea water violently stirred up with 

 oars will give a light and seem to burn, which kind of light the 

 Spaniards call the sea-lungs " (jellyfish) . 



Kene Descartes and Jacques Rohault 



Bacon merely mentioned the phenomenon. A very definite expla- 

 nation of the cause of sea light came from Rene Descartes (1596- 

 1650) . In his discourse on Les Meteores, published in French at 

 Leyden in 1637 and in the Latin Principia in 1644, Descartes at- 

 tempted to explain many natural phenomena. Among other things 

 he discussed 



why sea water is less suitable to extinguish fire than river water, and 

 why it shines during the night when stirred up; for you should realize 

 that the particles of salt, being easily set in motion because they are, so 

 to speak, in suspension between particles of fresh water and possessing 

 much momentum once they are stirred up because they are straight and 

 inflexible (rigid) , are capable not only of causing the flames to flare up 

 when they are thrown into a fire, but also of emitting flames themselves 

 when shooting out of the water in which they are.^ 



* The word " fire " was regularly used in connection with the sea. Wm. Dampier 

 (1652-1715) wrote: " The Sea (near Hong Kong) seemed all of a Fire about us, for 



every wave that broke sparked like lightning." From Dampier's voyages, ed. by John 

 Masefield 1: 409, London, 1906. 



^ Bacon, F., 1622, History of winds, trans, by R. G., 234. 



* From a translation by Professor Gilbert Chinard of Princeton University of the 

 (Euvres de Descartes, published by Charles Adam and Paul Tannery, 4: 255-256, Paris, 

 1902. 



