25 2 NATURAL HISTORY 
horfes we obferved it, but almoft extinguifbed, only a fpark here 
and there. At Newton, two miles thence, we viewed it by candle- 
light, as alfo the next day, and found it coarfe, fpiry grafs, of an 
inch or little more in length, fuch as ordinarily grows on downs 
The caufe of this luminous appearance has been varioudy affigned ; 
fome have thought it owing to a certain bituminous matter thrown 
up by a fermentation, or fleams afcending from the bottom of the 
fea 0 : But this is too limited a caufe, and will by no means ac- 
count for like appearances by land ; indeed nothing of a bitumen 
appears, neither do waters of any kind become luminous unlefs firft 
ftirred and agitated, neither does kindled bitumen make fo harmlefs 
a fire, nor continue fhining fo long, nor expire fo gradually. Others 
have thought it part of that eledric fire, which (as every one is 
now convinced) is diffufed throughout the univerfe; but this elec- 
trical fire becomes only vifible by flafhes, pafiing in inftantane- 
ous fallies from one body to another, and immediately expiring ; 
and a learned gentleman* (as I am informed) who had formerly 
efpoufed this caufe, concludes ingenuoufiy from farther experiment, 
that this luminous appearance is not owing to eledtric fire produced 
between the particles of water and thofe of fait, as he had firft 
imagined, but to fome other caufe. 
Dr. Plot (Staffordfhire, page n6) hints, that the fhining of 
the mire and miry water, may be owing to a kind of glow-worm ; 
thus the clammy moifture of oyfter-fhells which fhines in the night 
of a violet colour, comes from luciferous worms that have their 
holes in the fhells p ; and this hint has been adopted, and farther 
purfued by fome modern authors of reputation ", who are of opinion, 
that this fliining light is owing to a multitude of animalcules rifing 
to the furface of the fea in the night, and throwing forth their 
light (like glow-worms) when they are agitated. This hypothefis 
is confirmed by the late experiments of a learned Italian, Dr. Vi- 
anelli of Chioggia, who carrying home a veffel full of the lumi- 
nous water of the lake of Chioggia, and ftirring it in a dark 
clofet with his hand, found that it glittered much ; but after 
filtrating it through a piece of coarfe linen, that it fhone no 
more : the piece of linen however was covered with lucid parti- 
cles, which in a microfcope he difcovered to be animalcules entirely 
luminous 1 . In all the forementioned cafes of mire, lake, and fea, 
there is none of this fhining without water ftirred : it is therefore 
an aquatic glow-worm s of a different element from that of the 
n Dr. Birch’s Hift. of the R. S. vol. I. pa. 431. 
0 Natural Hiftory of Waterford, page 290. 
* Mr. Franklyn. 
f Ibid, from Mr. Auzout. 
h Mr. l’Abbe de Nollet, and others. 
' Since Vianelli another Italian author. Dr. 
Grifelin, has purfued and farther elucidated the 
fame fubjecf. 
5 It is called Nereis phofphorans ; alias, Sco- 
lopendra marina lucida. 
land, 
