On the luminous Appearance of Sea Water. 20/ 



agitated) occasionally exhibits, and the desire satisfactorily 

 to account for this phenomenon, have caused much investi- 

 gation ; but throughout the whole T do not recollect that 

 any thing like the phaenomena stated below has been ob- 

 served. 



Believing then the fact to be new, I venture to request 

 you will give it a place in your Magazine; and I indulge 

 the hope that it may lead to a further and profitable dis- 

 cussion of the subject. 



On the 8th of August last, in the evening, being at 

 Blackpool on the western coast, and observing the sea to 

 be at times very luminous^ — 1 went to the beach, in order 

 to view it more clearly. And accidentally stamping on a 

 flat part where the tide had flowed, but from which it had 

 receded a few feet, it being about half an hour after hit^h 

 water, I was surprised with the appearance of some hun- 

 dreds of sparks of light, which surrounded my foot in every 

 direction, to the distance of about 13 inches, the largest 

 being nearest. The light, however, was only instantaneous. 



Struck with the novelty of the appearance, I stamped a 

 seccmd time on the same spot, and produced a very few 

 sparks ; I afterwards stamped repeatedly on the same spot, 

 but withoirt producing any. I then sought for a similar 

 flat spot on the beach ; and, stamping upon it, I produced 

 the same appearances as in the first case. I then tried to 

 elicit sparks by stamping on the sloping part of the beach 

 which inclines to the sea, but without success : on trying 

 again, however, on the flat parts, the same appearances in- 

 variably occurred. 



Unvvilling that so singular a fact should rest on the 

 dictum of an individual, I requested L. Starkie, esq. of 

 Huntroyd, in thai neighbourhood, to accompany me to the 

 beach ; where we repealed the experiment several times 

 with the same success. 



It seems therelore that the tide at high water had depo- 

 sited something in these flat places; and that the friction 

 of the shingles against each other, produced by the stamp- 

 ing, was the cause of this matter emitting the luminous 

 appearances: the tide had eflectually left the beach, and 

 there was not the least appearance of puddles of water in 

 the places acted upon. 



I am, sir. 



Your obedient servant, 



Surry In.titution, KnIGHT SpENCER. 



Sept. 2. \%i%. 



XXXVUI. De- 



