Phosphorescence of the Sea 529 



sea light or " phosphoreal light " resulted from several causes— that 

 there were in fact three kinds of sea light. One kind was observed 

 mostly during a fresh gale, near the ship or on nearby waves, and 

 resulted from the ship's disturbance. It was regarded as electrical, 

 owing to rubbing of the hull of the ship as it passes through the 

 water. The second sort of luminescence was observed only during a 

 calm. It extended far from the ship and deeper in the water and 

 was due to a " real phosphoreal light " of decomposing animal parts, 

 all of which contain phosphorus in the form of an acid. " Everyone 

 who has seen salted fish drying must know that many of them become 

 phosphoreal." The third type of light was due to medusae and other 

 " live animals floating in the sea and is owing to their peculiar struc- 

 ture or rather the nature of their integiant parts," which Forster 

 said should be analyzed chemically to find out the origin of the light. 

 Several writers at the end of the eighteenth century prepared 

 general articles on sea light, reviewing previous observations without 

 taking too definite a stand on the origin. Such a review is to be 

 found in the article on " Mer Lumineuse ou Noctilucum Mare," 

 in Valmont-Bomare's Dictionnaire Raisonne Universal d'Histoire 

 Naturelle 8: 396-407, 1791. Another was by Johann Georg Ludolf 

 Blumhoff (1774-1825) , professor of technology at Giessen, in 1797. 

 A translation appeared in the Philosophical Magazine for 1800, 

 which indicated that Blumhoff was inclined to favor the Forster 

 notion of three kinds of sea light. Another review was that of Tingry 

 (1798) , " De la phosphorescence des corps et particulierement sur 

 celles des eaux de la mer," published in Delametherie's ]ournal de 

 Physique. 



Early Nineteenth-Century Views 



FRANCOIS PERON 



At the beginning of the nineteenth century there was a growing 

 tendency especially among naturalists, to attribute all sea light to 

 living organisms of one kind or another. The belief is very forcibly 

 expressed by Francois Peron (1775-1810) , whose travels to Australia 

 and New Zealand in 1800-1804 gave him abundant opportunity for 

 observation. After pointing out that phosphorescence appears in the 

 seas but is more apparent under certain conditions, Peron (1804) 

 wrote: 



All the phenomena of the phosphorescence of sea water, however multi- 

 plied and singular, are ascribable to one cause, the luminousness attached 

 to sea animals, and most especially to molluscae, and other soft zoophytes. 

 My numerous experiments, and the beautiful series of phosphorescent 



