AN ESSAY TO SHEW THE CAUSE OF ELECTRICITY; AND Why Some Things are Non-Electricable. In which is also Consider’d Its Influence in the _Blasts_ on Human Bodies, in the _Blights_ on Trees, in the _Damps_ in Mines; and as it may affect the _Sensitive Plant_, &c. In a LETTER To Mr. WILLIAM WATSON, _F.R.S._ By JOHN FREKE, Surgeon to _St. Bartholomew’s_ Hospital, _London_, F.R.S. _Naturam expellas furcâ, tamen usque recurret._ The SECOND EDITION: With an APPENDIX. _LONDON:_ Printed for W. INNYS, in _Pater-noster Row_. MDCCXLVI. [Price One Shilling.] ------------------------------------------------------------------------ TO _MARTIN FOLKES_, Esq; PRESIDENT OF THE ROYAL SOCIETY. _SIR_, Those who have the Honour of your Acquaintance, and thence know your many excellent Qualifications, must applaud my Choice in dedicating this small Piece to you; whose Name, if there be any Merit in the Performance, will, before any other, add a Lustre to it. I am, with the highest Esteem, _Your most Obliged, Humble Servant_, JOHN FREKE. ------------------------------------------------------------------------ The PREFACE. _When I first enter’d on this Subject of _Electricity_, I intended only to put some Thoughts in Writing concerning it, that I might the more easily convey them to the Understandings of such as I hoped would be more likely than I should be to go farther with it. And as nobody, either here or abroad, had published any thing touching the Cause from which it was produc’d, I chose to shew the Beginning I had made to some Friends, whose Opinion concerning Natural Knowlege I had a great Reliance on. I told them, I thought my Difficulty would be to convey what I had to propound on this new Subject to them with the necessary Clearness, as my Intention was to observe the utmost Brevity in it._ _After I had read it to them, they assured me that what I had written was perfectly intelligible; and that it gave them many new Ideas respecting this _Phænomenon_; and were very earnest with me to print it, for the sake of the Publick._