In the summer of 1866, the author of this little book, moved by the repeated and earnest solicitation of his Medical Classes, prepared and printed a small pamphlet entitled Practical Principles of Medical Electricity, designed more particularly, as the present work also is, as a Hand-Book to assist the memory of those who have taken a regular course of LECTURES from himself, or from some other competent instructor in the same general system of Practice. The edition of that work was exhausted somewhat more than a year ago. Still, the book has continued to be frequently called for. The author has, therefore, prepared, and now.