In making our epitome, we have often written without a special reference to any book; sometimes we have abridged the writings of others; sometimes we have taken paragraphs with the alteration of a few words; and sometimes we have introduced full quotations. In the latter case, we have always wished to make a distinct reference to the author quoted; and in other cases, we have generally made our acknowledgments where we were particularly indebted. But as our work was begun without any determination to publish it, we have probably made some selections, of which we have ourselves forgotten the authors from whom they were taken. Of the fairness of a work of this nature, we suppose there can be no question. Johnson, when speaking of the system of logic published by Watts, has made our apology—“If he owes part of it to Le Clerk, it must be considered, that no man who undertakes merely to methodise or illustrate a system, pretends to be its author.” As impositions are often attempted, by soliciting patronage for publications of little value, we felt the importance of obtaining, in behalf of our work, the approbation of competent judges—The public will admit that it has been obtained; and the professional gentlemen who have favoured us with it in the most obliging and disinterested manner, will excuse our offering them this public tender of our grateful acknowledgments. With these remarks we commit our little work to the candour of the public, conscious of having assiduously laboured to furnish a book which, though it appeared to us to be much wanted, had not yet been written or compiled. Our views will be fully answered, if it shall be found well adapted to assist youth in their academical and philosophical studies, and at the same time, to afford amusement to men of learning, and some useful information to gentlemen of leisure. INTRODUCTION. SECTION I. _Electricity as known among the Ancients._ In examining the progress of almost any branch of human knowledge, curiosity must meet with many repulses. By the time the attention of society is attracted to the accumulation of detached truths, which compose a science, it is often impossible to retrace its history. The real origin of most discoveries is obscured by antiquity, their authors have already sunk into oblivion, and important improvements are ascribed to different inventors.