The desire of longevity appears to be inherent in all animated nature, and particularly in the human race; it is intimately cherished by us, through the whole duration of our existence, and is frequently supported and strengthened, not only by justifiable means, but also by various kinds of collusion. Living in an age when every branch of human knowledge is reduced to popular systems; when the vigils of reason are hallowed at the shrine of experiment and observation;--though we behold in the immense variety of things, the utter uselessness of attempting to renovate a shattered constitution, or of improving a sound one to last beyond a certain period; we nevertheless observe that in the inconceivable waste of elementary particles there prevails the strictest economy. Nothing is produced in vain, nothing consumed without a cause. We clearly perceive that all nature is united by indissoluble ties, that every individual thing exists for the sake of another, and that no one can subsist without its concomitant. Hence we conclude, that man himself is not an insulated being, but a necessary link in the great chain, which connects the universe. Nature is our safest guide, and she will be so with greater certainty, as we become better acquainted with her operations, especially with respect to those particulars which more nearly concern our physical existence. Thus, n source of many and very extensive advantages will be opened; thus, we shall reach our original destination--namely, that of living long and in the enjoyment of sound health, to which, if purity of morals he added, the best hopes may be entertained of a happy state, in a future world, where its inhabitants never die.