Phosphorescence of the Sea 525 



J. Bressy (1800) also, had developed a machine for electrifying 

 water in motion. Since the sea was always in motion and sea phos- 

 phorescence, particularly, resulted from movement, he naturally con- 

 sidered the light to be electrical in origin. Henry Robertson, a 

 physician to the Duke of Kent, as late as 1819, also considered sea 

 luminescence electrical. 



MECHANICAL 



An example of the mechanical point of view was that held by 

 M. de la Coudreniere (1775) . He expressed surprise that celebrated 

 physicists should consider sea light (" ce meteore marin ") due to 

 " insects " which they have seen in seaweed. Coudreniere held that 

 it was more like " meteores phosphoriques," characteristic of the 

 surface itself. He said that a blow on the surface would always 

 render the sea luminous during any season or in any climate. Olaf 

 Wasstrom "- (1798), who described light from ice when broken, 

 suggested that light of the sea was due to small ice crystals in the sea 

 water which flashed when broken by waves. L. Brugnatelli (1797) , 

 who had studied the luminescence of crystals when rubbed together, 

 also thought that sea light was a similar mechanical though invisible 

 accumulation of a light-substance by movement. 



INSOLATION 



We have seen that as early as the late seventeenth century, Pere 

 Tachard attributed (1688) the light of the ocean to " igneous par- 

 ticles with which the sun has impregnated the sea during the day, 

 that assemble and escape, going out in a violent state at night." The 

 idea that phosphorescence of the sea came from the sun persisted 

 for many years. It was generally held in Sweden, according to Erich 

 Pontoppidan (1698-1764) , Bishop of Bergen, a writer on natural 

 history. After speaking of the " unctuousness of the sea " which 

 " has probably some connection with its effulgence and scintilla- 

 tions " and is called " Moorild " by sailors, he wrote: -^ " Mr. Urban 

 Hierne, the Swedish naturalist who derives sea salt from the sun 

 judges this sea light to be a kind of phosphorus, formed from the 



-^Neue Schwedische Abhmidlungen 1798, with a translation in Crell's Chem. Ann., 

 392, 1799. J. Weber (1892) described " Feuerstrahlen " from ice in the Donau, and 

 Heinrich (1820: 482) discussed reports of tribolinninescent ice. In more recent times, 

 J. Precht (Physik. Zeit. 3: 457-459, 1902) observed luminescence of ice at liquid air 

 temperature. 



-^ Pontoppidan, E., The natural history of Norway, translated from the Norwegian, 

 73-75, London, 1775. In 1765 another Norwegian bishop, Erik Schyttes, distilled sea 

 water which exhibited " moorild " (sea light) , and found that the luminescent material 

 did not pass over with the distillate, but was permanently quenched. 



