INTRODUCTION.
The ultimate object of animal life being pleasure, the law of self-preservation, or the love of life, will remain in full force so long as the sensations of pleasure are not outweighed by those of pain, or until the organs of sense become indifferent to their accustomed stimuli. Every creature, therefore, is so wisely constructed, and endowed with such instincts, as induce it to make choice of those means which are best calculated to maintain and preserve its existence: were not this the case, animal life would soon terminate.
But as individual life has a commencement, so also has it an end; and though the laws of nature should be at all times implicitly obeyed, and circumstances should be of the most favorable kind, yet there is a limit beyond which none can pass,—when vitality must yield to the universal range of chemical influence. Even man, the last and most complete result of Divine workmanship, is no exception to this general rule; nor can all his wisdom and intelligence reveal to him the means of escaping the sentence passed upon the father of our race: "Dust thou art, and unto dust shalt thou return!" This, however, should not deter him from investigating the laws of mortality, and the causes which hasten or protract the period of old age and death. "Know thyself!" was the advice of the ancient sage; and it is still further enforced upon our attention by the well known line of Pope,—
"The proper study of mankind is man."
It should, indeed, be our first endeavor to become acquainted with our position in the universe;—to mark the relation in which we stand to surrounding objects; to inquire how health and happiness, present and future, may be best promoted; diligently and faithfully to examine in what cases we have misconceived or departed from the laws of nature, by the observance of which health may be maintained, and longevity promoted; and, finally, to ascertain by what means physical and moral evil may be diminished, and the universal reign of peace and harmony established.
The man who would enjoy the greatest happiness for the longest period
