516 History of Luminescence 



nous animals of the sea. Lack of observation is particularly hard to 

 understand in the case of Leeuwenhoek, the discoverer of bacteria, a 

 person living near the sea and one who subjected every possible 

 object to the scrutiny of his lenses. It was reserved for another 

 microscopist, Henry Baker, nearly a century later, in 1753, to pub- 

 lish the first clearly recognizable description of the luminous marine 

 protozoan, Noctiluca. 



Father Bourzes and French Observations 



With the beginning of the eighteenth century, attempts to ascer- 

 tain the true cause of the light of the sea became more experimental. 

 One of the first to apply this approach was Father Bourzes (1708) , 

 a Jesuit missionary, who made a trip to the East Indies in 1704. 

 After describing a remarkable phosphorescence observed in the In- 

 dian Ocean, July 10, 1704, bright enough to read by, he wrote ^^ a 

 letter to Father Estienne Souciet, which was published in the Philo- 

 sophical Transactions for 1713: 



If one takes some Water out of the Sea, and stirs it never so little with 

 his Hand in the dark, he may see in it an infinite number of bright 

 Particles. Or if one dips a piece of Linnen in Sea Water, and twists or 

 wrings it in a dark Place, he shall see the same thing; and if he does so, 

 though it be half dry, yet it will produce abundance of bright Sparks. 

 When one of the Sparkles is once formed, it remains a long time; and if 

 it fix upon any thing that is solid, as for instance, on the side or edge 

 of a Vessel, it will continue shining for some Hours together. It is not 

 always that this Light appears, tho' 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 I have observ'd 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. 



The Production of this Light depends very much on the Quality of 

 the Water. . . . And I have often observed, that when the Wake of the 

 Ship was brightest, the Water was more fat and glutinous; and Linnen 

 moisten'd with it produced a great deal of Light, if it were stir'd or mov'd 

 briskly. Besides, in sailing over some Places of the Sea, we find a Matter 

 or Substance of different Colours, sometimes red, sometimes yellow. In 

 looking at it, one would think it was Saw-dust: Our Sailors say it is the 

 Spawn or Seed of Whales. What it is, is not certain; but when we draw 

 up Water in passing over these Places, it is always viscous and glutinous. 

 Our Mariners also say, That there are a great many Heaps or Banks of 



^2 Bourzes, Phil. Trans. 28: 23S-234, 1713, and Jones' Abridgment of the Phil. Trans. 

 5 (2) : 213, translated from " Lettres edifiantes et curieuses." 



