54 PHILOSOPHICAL TRANSACTIONS. [aNNO 1713. 



6. At such times as we could distinguish tlie bright parts from the others, we 

 observed that they were not all of the same figure; some of them appeared like 

 points of light; others almost as large as stars, as they appear to the naked eye. 

 We saw some that looked like globules, of a line or two in diameter; and 

 others like globes, as large as one's head. These phosphori often formed 

 themselves into oblongs, of 3 or 4 inches long, and I or 2 broad. Sometimes 

 we could see all these different figures at the same time. Another day when 

 our ship sailed slowly, the vortices appeared and disappeared again immediately, 

 like flashes of lightning. 



7. Not only the wake of a ship produces this light, but fishes also in swim- 

 ming leave behind them a luminous track ; which is so bright, that one may 

 distinguish the size of the fish, and know of what species it is. I have some- 

 times seen a great many fishes playing in the sea, which have made a kind of 

 artificial fire in the water, that was a very pleasant sight. And often only a 

 rope, placed crosswise, will so break the water, that it will become luminous. 

 8. If one take some water out of the sea, and stir it ever so little with his 

 hand in the dark, he may see in it an infinite number of bright particles. 9. Or 

 if one dip a piece of linen in sea water, and twist or wring it in a dark place, 

 he will see the same thing, and if it be even half dry. 



10. When one of the sparkles is once formed, it remains a long time; and 

 if it fix upon any thing that is solid, as on the side or edge of a vessel, it will 

 continue shining for some hours together. 11. It is not always that this light 

 appears, though the sea be in great motion ; nor does it always happen when 

 the ship sails fastest; neither is it the simple beating of the waves against one 

 another that produces this brightness, as far as I could perceive; but 1 have 

 observed that the beating of the waves against the shore has sometimes produced 

 it in great plenty ; and on the coast of Brazil the shore was one night so very 

 bright, that it appeared as if it had been all on fire. 



\2. The production of this light depends very much on the quality of the 

 water; and, if I am not deceived, generally speaking, I may assert, other cir- 

 cumstances being equal, that the light is largest when the water is fattest and 

 fullest of foam; for in the main sea the water is not everywhere equally pure; 

 and sometimes linen dipped into the sea is clammy when it is drawn up again. 

 And I have often observed, that when the wake of the ship was brightest, the 

 water was more fat and glutinous; and linen moistened with it, produced a great 

 deal of light, if it were stirred or moved briskly. 



13. Besides, in sailing over some places of the sea, we find a matter or sub- 

 stance of different colours, sometimes red, sometimes yellow. In looking at 

 it, one would think it saw-dust ; our sailors say it is the spawn or seed of whales. 



