PREFACE.

THE subject of human Life and Death is, of all natural subjects, the most interesting to men; and, as such, the author has treated it with uncommon diligence. The enquiry is conducted in the inductive method; and carried to a considerable length: with directions for continuing it still farther, till we arrive at a knowledge of the cause and form of life and of Death. The whole being left in such forwardness, it may naturally be asked why it has not been since brought nearer to perfection? The principal reason I can assign is, that physicians have been otherwise employed: and men of different professions seem discouraged from improving an art they do not practise. The disease is easier found than the remedy. Nor can a capital remedy, in this case, be expected till men shall, in some degree, have conquered their passions; and shew a less regard to private, and a greater to public good. The author, has shewn by an illustrious example, that persons of a public spirit, might, though they were not bred to

physic, treat the subject of Life and Death to advantage.

That the full scope and conduct of the piece may be understood, it will be proper to remember the doctrine laid down in the second part of the author's Novum Organum; concerning the method of prosecuting enquiries.

INTRODUCTION.

THE shortness of life, and the slow advancement of arts, has been an ancient complaint. It is therefore agreeable to our design of bestowing the utmost pains upon the perfecting of arts, to consider also the ways of prolonging human life. But this enquiry is pressed with difficulties; the rather, because of false notions and opinions concerning it : for what the physicians have frequently in their mouths about radical moisture, and natural heat, are but delusory conceits; and the extravagant commendations of chemical medicines, do but first swell up, and then disappoint our hopes.*

The present enquiry is not directed to that kind of death which proceeds from suffocation, putrefaction, and diseases; for this belongs to medicinal history : but to that death only, which comes on by resolution, and a wasting of the parts, through old-age. The last step, indeed, of death, or the total extinction of life, (which may happen so many ways, both external and internal; though they have all of

*The virtues of pharmaceutical preparations are so unsettled, that it is generally little more than levity, to extol or decry particular remedies. See the Introduction to the Sylva Sylvarum.

them, as it were, one common avenue at last,) has some relation to our design and brings up the rear of the enquiry.

Whatever may be gradually repaired, without destruction to the original whole, is, like the vestal fire, potentially eternal: whence physicians and philosophers, observing that animals are totally nourished, aud their bodies recruited and supplied, though not for any long continuance; but soon after grow old, and hasten to a dissolution; they have sought for death in a subject not properly capable of repair; and judged, that a certain radical, and primitive moisture, could not be totally recruited; but that there was a certain spurious apposition of parts, and not a just repair, carried on from infancy, and gradually degenerating with age; till, at length, this depravity ends in non-existence.

This is but a crude and flashy notion; for all the parts of an animal in youth, and in a growing state, are totally repaired; and, for a time, not only improved in quality, but augmented in quantity: insomuch that the recruiting matter might be, in some measure eternal, if the manner of recruiting did not fail. But here lies the case, that in declining age, the repair is made very unequally; some parts being successfully nourished, but others with difficulty, and for the worse: so that from this time, animal bodies begin to suffer the mezentian torment, of having the live parts die in the embraces of the dead ones; those that are easily reparable failing, through their conjunction with such as are not for when age is upon the decline; the spirit, the blood, the flesh, and the fat, are easily repaired; but the dryer, or more spongy parts; the membranes, the coats, the nerves, the arteries, the veins, the bones, the cartilages, most of the viscera, and nearly all the organical parts, are repaired with difficulty and loss.

And as these parts must of necessity officiate in the actual repair of the more reparable parts; but, being thus diminish'ed in their activity and powers, can no longer perform their