ed, without observing any thing of use, as to the beginnings, the means, and the ends of dryness and consumption.

The process of dryness and consumption consists in three actions, and these actions have their origin from the native spirit of bodies, as was before observed.

The first action is the attenuation of moisture into spirit; the second is the exit or escape of the spirit; the third is the immediate contraction of the parts of the body after the spirit is gone : and this last is that desiccation and induration we are now principally concerned with, the two former tending only to consume.

In the case of attenuation the thing is manifest; for the spirit included in all tangible bodies operates without ceasing, and whatever it lays hold of, can digest, and work upon, it converts into itself, entirely changes, subdues, multiplies itself thereon, and begets new spirit. This receives an eminent confirmation from hence, that bodies much dried lose in weight, become hollow, spungy, and sonorous from within; whilst it is certain that the internal spirit contributes nothing to the weight of the body: whence it necessarily follows, that the internal spirit must have converted into itself the moisture and juice of the body which before had gravity, whence the diminution of the weight. And this is the first

5

action; viz. the attenuation of the moisture and its conversion into spirit.*

The second action; viz. the escape or avolation of the spirit, is likewise manifest; for when this happens largely, it is apparent even to the sense, in vapours to the sight, and in odours to the smell; but when it happens gradually, as it does through age, it is then performed insensibly; though the case, in effect, be the same. And where the texture of the body is so close and tenacious that the spirit can find no pores or passages, at which to issue; here also, in its endeavour to get out, it drives the grosser parts of the body before it, and thrusts them above the surface which is the case in the rusting of metals, and the corruption of all fat bodies.

The third action is somewhat obscure, but no less certain than the others, being a contraction of the grosser parts, after the spirit is discharged. And, first, we see that bodies manifestly shrink, and possess less space, after the exit of the spirit; as we find in nut-kernels, which when dried do not fill the shell: and again, in boarding and paling, where the several planks, or pieces of wood, are laid close together at first; but gape and shrink from each other when dried. In like manner bowls, and other wood-work, crack and

* What this internal spirit is, see below Sect. XI.

split with dryness; whilst the parts contract themselves, and thus of necessity leave empty spaces between. Secondly, this appears from the wrinkling of dry bodies: the endeavour of contracting themselves being so forcible as to bring the parts together, and raise them up; for whatever is contracted in the extremities must rise up in the middle, as we see in paper, parchment, the skins of animals, and in the coat of soft cheese: all which grow wrinkled with age. Thirdly, this contraction appears still more remarkably in such things as do not only wrinkle, but twist, curl up, and roll themselves round with heat; as parchment, paper, and leaves do when exposed to the fire: for contraction, through age, proceeding but slowly, generally produces wrinkles; whilst contraction by the fire, being sudden, causes curling. But in many bodies where neither wrinkling nor curling can happen, there ensues a bare contraction, shrinking, hardness, and dryness, as we first observed. But if the spirit be so far exhaled, and the moisture so consumed, as not to leave enough of the body to unite and contract itself, then all contraction necessarily ceases; the body becomes rotten, and no more than a heap of dust, clinging together, which is dissipated by a slight touch, or thrown off into the air; as we see in all bodies greatly consumed; viz. paper and linen, burnt to the ut

most; and in dead bodies embalmed after lying

many ages.

It must be observed that fire and heat only dry by accident; for it is their proper office to attenuate and dilate the spirit and the moisture: but it follows by accident, that the other parts contract themselves, either to prevent a vacuum, as the vulgar phrase is; or by the concurrent action of some other motion, about which we are not now enquiring.

It is certain that putrefaction, as well as arefaction, has its origin from the native spirit; though it proceeds in a very different way: for, in putrefaction, the spirit not being simply discharged, but in part detained, has strange operations and effects; whilst the grosser parts also suffer, not a local contraction, so much as a joint and homogenious union.*

SECT. IV.

THE HISTORY OF THE LENGTH AND SHORTNESS OF LIFE
IN ANIMALS; PURSUANT TO THE THIRD ARTICLE
OF THE TABLE OF ENQUIRY.

WITH regard to the length and shortness of life in animals, the information procurable is but

* See the article Putrefaction, in the Sylva Sylvarum.

slender, observation slight, and tradition fabulous. Tame creatures are corrupted by a degenerate life; and wild ones

intercepted by the in

Neither do the things

clemency of the weather. which may seem concomitant assist us much in this enquiry; as the bulk of the body, the period of gestation, the number of young, the time of growth, &c. these being complicated considerations, that sometimes concur and sometimes not.

The age of man, so far as can be collected from certain history, exceeds that of all other animals, excepting a very few; and the concomitants in him are found tolerably equable: his size and stature large, his period of gestation nine months, his offspring generally single, his time of puberty at fourteen, and his growth reaching to twenty years.

The elephant certainly exceeds the ordinary age of man; their period of gestation is not ten but two years, or at least above one; their bulk vast; their growth till thirty; their teeth exceeding strong their blood is observed to be the coldest of all animals; and they sometimes live two hundred years.*

Lions are thought to be long lived, because many of them have been found toothless; but

* See the account of elephants, in the Philosophical Transactions.