To Peter Collinson
Philada Augt 14, 1747.
Sir
I have lately written two long Letters to you on the Subject of Electricity, one by the Governor's Vessel, the other per Mesnard. On some further Experiments since I have observ'd a Phenomenon or two, that I cannot at present account for on the Principle laid down in those Letters, and am therefore become a little diffident of my Hypothesis, and asham'd that I have express'd myself in so positive a manner. In going on with these Experiments how many pretty Systems do we build which we soon find ourselves oblig'd to destroy! If there is no other Use discover'd of Electricity this however is something considerable, that it may help to make a vain man humble.
I must now request that you would not Expose those Letters; or if you communicate them to any Friends you would at least conceal my Name. I have not Time to add but that I am, Sir,
Your obliged and most hume Servt
B. Franklin.