74 NATURAL H I S T OR Y of NO R TFA T. 



judges this fea-light to be a kind of phofphorus, formed from the 

 luminous particles of the fun, and even of the moon, impregnated 

 by water ; as is the cafe in the Lapis Bononienfis, and Baldwin's 

 phofphorus. But inftead of refting in thefe, or other conjectures, 

 I am much more inclined to declare my opinion, that this other- 

 wife inexplicable phenomenon in the fea, has been befl; illuftrated 

 (tho' with room for many additions) by a little piece lately pub- 

 lished at Venice, with the title of Nuovo Scoperto Intorno di 

 luci Notturne dell' Aqua Marina. Having no opportunity of fee- 

 ing the original, I am the more obliged to the diligent and in- 

 genious authors of the New Copenhagen Literary Journal, who 

 have given us the fubftance of it in the xxxixth part, of the -24th 

 of Sept. 1750, in the following words, " Our author is the firft 

 who has explained the true caufe of this corufcation : He has 

 obferved, that in the gulph of Venice, the water is luminous 

 only from the beginning of fummer till the end of harveft, and 

 that this light is moft copious in places abounding with fea-grafs ; 

 and ftill more when the water is put in motion, either by the 

 winds, mips, or oars. In 1 746, the author filled a flafk with this 

 fcintillating water, and carried it home ; but it emitted no light, 

 except only when flirred in the dark, it immediately fparkled. He 

 clofely inlpecled it in the day-time, in order to difcern whether 

 the water had any thing heterogeneous in it, from whence thefe 

 emanations of light proceeded ; but nothing of this kind appeared 

 to the naked eye : he therefore ftrained the water through a clofe 

 fine cloth, the confequence of which was, that the cloth fhone 

 in the dark, but not the water, however fhaken or flirred. This 

 inclined him to judge, that the lucid fubfknce in the water was 

 fomething diftincl from the water itfelf, especially as he perceived 

 the light, which the cloth emitted, to confift of innumerable lu- 

 cid particles or points ; but not having a microfcope at hand, he 

 could take no minute view of them. Having fome time after pro- 

 cured a microfcope, he gathered fome fea-grafs, which is moft apt 

 to glitter in the night, and upon examining it in a dark place, he 

 difcerned above thirty of thefe lucid particles on one fingle leaf. 

 He fhook this grafs over a meet of paper, when one of thefe par- 

 ticles fell off , it was as fubtile as an eye-lafh, and about as long,, 

 and the colour a black yellow : he now made ufe of the micro- 

 3 fco P e * 



