Young men are full of hope and confidence; but old men diffident, and in most cases distrustful.

Young men have an easy and obliging carriage; but old men are churlish, peevish, and disdainful.

Young men are sincere, and speak their minds; but old men are cautious and reserved.

Young men affect great undertaking; but old ones take care of such things as are necessary. Young men favour things present; but old ones rather affect former transactions.

Young men reverence their superiors; but old men censure them.

There are numerous other differences, which belong rather to morality than the present enquiry. Yet as old mens' bodies improve in some respects, so likewise do their minds : unless quite worn out for example, though they are less ready at invention, they are stronger in judgment; and chuse such things as are safe and solid, before such as are specious and showy. They likewise improve in talkativeness, and the art of shewing themselves to advantage; and, becoming now unfit for business, reap the fruits of discourse whence the poets aptly feigned the transformation of Tithonus into a grass-hopper.

SECT. XI.

IMPROVEABLE AXIOMS, OR VARIABLE CANONS, FORMED UPON THE PRECEDING HISTORY; FOR GIVING LIGHT INTO THE CAUSE OF THE CONTINUANCE OR DURATION OF LIFE, AND THE TRUE NA

TURE, OR FORM, OF DEATH.*

AXIOM I.

There is no consumption, unless what is lost by one body passes into another.

EXPLANATION.

There is no such thing as annihilation in nature; and therefore in all consumption, the parts

*This Section contains a kind of recapitulation, or concise abridgment, of the preceding history; drawn up with new enforcements, and set in a fuller light; whence a judgment may be the readier formed thereof. And certainly it must be a pregnant history, to afford such a number of axioms, that seem a little compendium of Natural Philosophy; at the same time that they unfold, and explain, some of the great mysteries of Life and Death. And hence also a tolerable judgment may be formed of the design of this part of the author's work, which was to receive a collection of still more perfect axioms, after they had been thoroughly verified, or rendered precisely just; at least so just as not to fail in practice.

consumed either fly off into the air, or are received into some adjacent body. Thus we see spiders, flies, ants, &c. included, and eternized in monuments of amber; though these are tender and dissipable bodies: but then there is no air in contact with them, for their parts to escape into; and the substance of the amber is so heterogeneous as to receive none of them. And the like effect, we judge, might be procured by burying wood, or the like, in quicksilver: but wax, honey, and gums, have this effect only in part.*

AXIOM II.

All tangible bodies contain a spirit, covered over, and inveloped with the grosser body; and this spirit it is that gives origin to consumption and dissolution.

EXPLANATION.

There is no known body, in the upper parts of the earth, without its spirit; whether it be generated by the attenuating and concocting power of the celestial warmth, or otherwise for the

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* These axioms require a considerable attention to perceive their full meaning and just value; a greater to improve and verify them, they may require it; and a greater still to explain them so as to render them universally intelligible: and draw them out into familiar rules of practice, for operating effectually in the grand design of prolonging life.

pores of tangible bodies are not a vacuum; but either contain air, or the peculiar spirit of the substance. And this spirit is not a virtue, an energy, a soul, or a fiction; but a real, subtile, and invisible body, circumscribed by place and dimension. Nor again is this spirit air, any more than the juice of the grape is water; but a fine attenuated body, of kin to air, though again, very different from it: for the grosser parts of the subject being of a sluggish and not very moveable nature, would endure to a long period, did not this spirit rouze, stimulate, undermine them, and prey upon the moisture of the body, and whatever else it can digest and convert into new spirit; till at length, both the spirit before included in the body, and that newly formed, gradually fly away together. This is excellently demonstrated from the diminution of the weight of dry bodies, through perspiration for all that which flies away, was not spirit at the time of weighing the body; but was spirit when it flew off.*

*This instance we meet with in nuts, the stones of fruit, &c. where the kernel dries and withers, as the spirit perspires through the shell and outward coats; without the entrance or admission of the external air. This axiom relating to the spirits of bodies deserves a particular regard. And let not any modern discoveries be too rashly imagined to have set the doctrine of spirits aside; whereon, perhaps, the improvement of natural philosophy principally depends.

AXIOM III.

The avolation of the spirit of bodies causes dryness; but whilst this spirit is detained aud operates within, it either dissolves, putrefies, or vivifies the body.

EXPLANATION.

There are four processes of the spirit; viz. 1. that of drying, 2. that of dissolving, 3. that of putrefying, and 4. that of generating bodies.

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Arefaction is not the proper operation of the spirit; but of the grosser parts, after the spirit is discharged for upon this they contract themselves, partly to fill up vacuities; and partly through an appetite which homogeneous bodies have to unite; as appears in all bodies dried by age, and in the firmer bodies which are dried by fire; as bread, charcoal, bricks, &c.

But colliquation is a mere work of the spirits; and not performed without the animation of heat; whereby the spirits dilate themselves, yet without flying off; and insinuate and spread among the grosser parts; thus rendering them soft and fusible; as we see in metals and wax: for metals, and other tenacious bodies, are fitted to hold

See the Sylva Sylvarum, under the articles Nature, Spirit, Sympathy, &c.