From personal experience and no inconsiderable range of observation, I am convinced that the author has by no means overrated the influence of imagination upon health and disease. It is indeed astonishing, at this late period, when every physiologist and physician is ready to proclaim his own recorded observations upon the medicinal influence of the moral powers, the passions, and especially the imagination, that so few medical men have thought it an object to employ them as elements of actual application. Hitherto these unknown and undefined powers of life and death have been in the hands of empirics, jugglers, mountebanks and pretended dispensers of miraculous healing. It is, at the same time, matter of regret, that scientific physicians, instead of questioning their undeniable cures, and pouring attempted ridicule upon them, have not separated the true from the false, and sought access to the real fountain of the efficacy of their practice, the employment of confident faith, hope, and the unlimited agency of the all pervading power of the imagination. Many physicians are sufficiently wise, and endowed with character, to exercise circumspection in giving their opinions and pronouncing upon the prognostics of their patients. They regulate their words, countenance and deportment with a caution and prudence which speak volumes in regard to their conviction of the influence which imprudence in these points might have. In fact, it is only necessary to observe the intense and painful earnestness with which the patient and the friends watch his countenance and behaviour, to be aware what an influence may be thus exerted. It is only requisite to understand with what prying anxiety the sick man questions those around him, what the physician thinks and predicts of his case, to make him sensible how vigilantly he should be on his guard, in spending his judgment rashly in the case. All this negative wisdom, in the application of moral means, is sufficiently common. Not to possess it, in a considerable degree, would indicate a physician unacquainted with the most common etiquette of a sick chamber. But, as yet, we see the positive employment of these means almost wholly interdicted by custom to regular physicians. We contend for their exercise only within the limits of the most scrupulous veracity and the most severe discretion. What powers would he not exert, who, snatching these moral means from the hands of empirics, and who, to thorough acquaintance with all that can be known in regard to physical means, should join the wise and discriminating aid of an imagination creating a healing world of hope and confidence about the patient? Such a benefactor of our species will, ere long, arise, who will introduce a new era into medicine.