Those who have done me the honor of reading my previous writings will probably receive no strong impression of novelty from the present volume; for the principles are those to which I have been working up during the greater part of my life, and most of the practical suggestions have been anticipated by others or by myself. There is novelty, however, in the fact of bringing them together, and exhibiting them in their connection, and also, I believe, in much that is brought forward in their support. Several of the opinions at all events, if not new, are for the present as little likely to meet with general acceptance as if they were.