L E

T T E R XII.

FROM

Benj. Franklin, Esq-, of Philadelphia ,

T O

Peter Collinson, Esq, F.R.S. London*

SIR , Philadelphia, September 1753J

I N my former paper on this subject, wrote first in 1747,enlarged and sent to England in 1749. I consideredthe sea as the grand source of lightning, imagining it&luminous appearance to be owing to electric fire, produc’dby friction between the particles of water and those of salt.Living far from the sea, I had then no opportunity of mak-ing experiments on the sea water, and so embraced this o-pinion too hastily.

For in 1750 and 1751, being occasionally on the seacoast, I found, by experiments, that sea water in a bottle,tho’ at first it would by agitation appear luminous, yet ina few hours it lost that virtue; hence , and from this, that Icould not by agitating a solution of sea salt in water pro-

duce