The publishers of this work offer no apology for presenting it to the reading public, since the wide prevalence of the evils which it exposes is sufficient warrant for its publication. The subjects with which it deals are of vital consequence to the human race; and it is of the utmost importance that every effort should be made to dispel the gross ignorance which almost universally prevails, by the wide diffusion, in a proper manner, of information of the character contained in this volume.