Transcriber's note: Text enclosed by underscores is in italics (_italics_). In view of the difficulty of reliably distinguishing 18th-century variant spellings from typographical errors, the text has been reproduced entirely as printed. * * * * * EXPERIMENTS AND OBSERVATIONS ON ELECTRICITY, MADE AT _Philadelphia_ in _America_, BY Mr. BENJAMIN FRANKLIN, AND Communicated in several Letters to Mr. P. COLLINSON, of _London_, F. R. S. * * * * * * _LONDON_: Printed and sold by E. CAVE, at _St. John's Gate_. 1751. (_Price 2s. 6d._) The PREFACE. _It may be necessary to acquaint the reader, that the following observations and experiments were not drawn up with a view to their being made publick, but were communicated at different times, and most of them in letters wrote on various topicks, as matters only of private amusement._ _But some persons to whom they were read, and who had themselves been conversant in electrical disquisitions, were of opinion, they contain'd so many curious and interesting particulars relative to this affair, that it would be doing a kind of injustice to the publick, to confine them solely to the limits of a private acquaintance._ _The Editor was therefore prevailed upon to commit such extracts of letters, and other detach'd pieces as were in his hands to the press, without waiting for the ingenious author's permission so to do; and this was done with the less hesitation, as it was apprehended the author's engagements in other affairs, would scarce afford him leisure to give the publick his reflections and experiments on the subject, finish'd with that care and precision, of which the treatise before us shews he is alike studious and capable. He was only apprized of the step that had been thus taken, while the first sheets were in the press, and time enough for him to transmit some farther remarks, together with a few corrections and additions, which are placed at the end, and may be consulted in the perusal._ _The experiments which our author relates are most of them peculiar to himself; they are conducted with judgment, and the inferences from them plain and conclusive; though sometimes proposed under the terms of suppositions and conjectures._ _And indeed the scene he opens, strikes us with a pleasing astonishment, whilst he conducts us by a train of facts and judicious reflections, to a probable cause of those phænomena, which are at once the most awful, and, hitherto, accounted for with the least verisimilitude._ _He exhibits to our consideration, an invisible, subtile matter, disseminated through all nature in various proportions, equally unobserved, and, whilst all those bodies to which it peculiarly adheres are alike charged with it, inoffensive._