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diseases cannot be prevented by a life of temperance, they can be cured at pleasure by medicine. This error, I regret to say, derives encouragement from the contradictory opinions promulgated in the numerous volumes which have issued from the press on the subject of health: many of them, while they affect to enlighten, tend only to confound and mislead, by involving doctrines in obscurity, and presenting such difficult and perplexing views of nature, as leave the mind of the reader disturbed indeed, but not convinced. the name of all that is consistent, if by our labours we cannot guide man into the right road, let us at least be careful not to lead him into the wrong, or, what is scarcely better, betray him into the depths of an impenetrable fog. Were it only for the benefit of the unprofessional reader, this subject should be treated with simplicity, and divested of technicalities. The grand object should be, to simplify practical knowledge, not to promote controversial disputation; for nothing can be more opposed to the general attainment of health and long life than the inculcation of a belief that they cannot be attained without difficulty. The endless recurrence of scientific phraseology has a direct tendency to discourage the unlearned inquirer, who, rather than give himself the trouble of understanding treatises so composed, and subject

himself to "be blown about by every wind of doctrine," passively resigns himself to the prevailing fashion, to which he speedily becomes so completely wedded as to feel angry whenever the wisdom of his conduct is called in question.

A little reflection will convince us that there can be no real difficulty or perplexity in the system of nature, nor the slightest obstacle to our pursuing it if we are so disposed. By following the dictates of this system alone, the attainment of health is rendered most simple, most easy, and most certain; but, if, on the contrary, we seek it in the popular modes of living, the search becomes most difficult, most delusive, and most certain of disappointment.

All the books that can be printed, all the arguments that can be adduced, and all the arts that can be devised, if they do not effectually move men from that universal conspiracy against themselves in their mode of living, in which they have so strangely consented, are but so many delusions, in so far as they may pretend to give lessons on the means of health and longevity. And in any attempts to dissipate this grand delusion, it should be ever borne in mind, that easy admission and positive conviction differ materially: the former is

not to be relied on, the latter only will affect the conduct; for

"He that's convinced against his will,

Is of the same opinion still."

But, before I can expect to implant in men's minds a thorough conviction of the truths I would inculcate, it is quite evident that I must first induce them to unlearn and abandon those errors* which have been consecrated by the acquiescence of ages. This is, indeed, a formidable enterprise; and, when it is considered that the most eminent and powerful writers on the subject have hitherto failed to prevail on the generality of mankind to alter their course of living, my boldness in undertaking it may savour perhaps of vanity.

"I know the warning voice is raised in vain,

That few will hear, and fewer heed, the strain."

COWPER.

Nevertheless, feeling, as I do, a consciousness of the purity and rectitude of my own motives in attempting to disperse the clouds of prejudice, I am encouraged by the belief, that, even among the millions led by the mere force of blind habit to

* Mal-information is more hopeless than non-information; for error is always more busy than ignorance. Ignorance is a blank sheet on which we may write ; but error is a scribbled one, on which we must first erase.

follow authorities grounded on absolute error, there may be some who, though they have hitherto disregarded the promptings of unerring nature, may, when the principles of the animal economy, together with a knowledge of the action of various substances upon the intestinal organs, are conveyed to them in a homely, unadorned, intelligible manner, begin to entertain a due esteem of that which formerly they thought beneath their notice, and be disposed to receive those lessons of experience whereby they will be enabled to decide, not on my mere dictum, but by the independent exercise of their own reason, what habits are calculated to injure, and what to benefit them. To such, therefore, I more particularly address myself.

I readily allow that it is difficult to prevail with men to abandon long-rooted habits in which they have the countenance of numbers; yet, so thoroughly convinced am I, that, however mankind may be infected by the contagion of errors, however men may erroneously regard a life of nature as opposed even to rational indulgence, however the force of custom may have reconciled them to absurdities, and though they may have pursued every sensual pleasure-so thoroughly convinced am I, notwithstanding all, that no man capable of

reflection exists, who, on being by patient demonstration and remonstrance made really sensible of the dangers he is hourly incurring, so long as he continues in a course of living opposed to nature, may not be induced to "consider his ways; and that, if such consideration lead, as it must, to a conviction that, by persisting in such a course, his life will inevitably be shortened, as well as his health ruined, he will lay a restraint on his unruly appetites-so thoroughly, I say, am I persuaded that the minds of men are open to conviction on this subject, if only well-directed efforts be made to convince them, that I by no means despair of succeeding, by the sincere and earnest application of my humble efforts, in an enterprise in which so many of my superiors in mere literary qualification have signally and disgracefully failed. I proceed, therefore, not only to point out the abuses which have gained such an ascendancy over men's understandings, but also to expose the causes in which those abuses have originated, and thus at once endeavour to strike at the root of a destructive error which has universally prevailed.

The only effectual mode of doing this, is to adduce such a combination of irrefragable proofs of the dangers attending the artificial state of