I do not here pretend to account for these Facts; that they are such is beyond Controversy, and I think it very agreeable to the Order of Nature, that they should depend upon some general Cause: If the Principle of Attraction be one, and from what Sir _Isaac Newton_ hath delivered in his Opticks it bids very fair for it, though that great Philosopher was either too modest, or too knowing, to propose it as such, otherwise than by way of Quære; if the Principle of Attraction be an universal Cause in such Effects as we have been speaking of, may it not very justly be supposed, that when animal Decoctions turn sowre by standing, and so far put on a vegetable Nature, as to differ from the Course animal Substances take, when left to themselves, that the Salts are disunited, and put from the Sphere of one anothers mutual Attraction, so as perhaps to exert a repelling Power; and may not the same thing happen, when putrified animal Substance becomes Nourishment for vegetable Bodies, their Salts being disunited, and their mutual Attractions dissolved or overcome by the Attraction of Water, Earth or other Parts, in the Substance which I before called vegetable Chyle? When Vegetables by Putrefaction acquire an animal Nature, are not the Salts brought into their Spheres of Attraction, so as to form different intestine Motions thereby, and to produce Heat, Fire, fetid Vapours, and Putrefaction? Sir _Isaac Newton_, Opt. p. 362. compares a Particle of Salt to a Chaos, dense, hard, dry, and earthy in the Center; and rare, soft, moist and watry in the Circumference, and hence, says he, it seems to be that Salts are of a lasting Nature, being scarce destroyed unless by drawing away their watry Parts by Violence, or by letting them soak into the Pores of the central Earth, by a gentle Heat in Putrefaction, until the Earth be dissolved by the Water, and separated into smaller Particles, which by Reason of their smallness make the rotten Compound appear of a black Colour. Hence also it may be that the Parts of Animals and Vegetables preserve their several Forms, and assimilate their Nourishment; the soft and moist Nourishment easily changing its Texture by a gentle Heat and Motion, till it becomes like the dense, hard, dry, and durable Earth in the Center of each Particle. But when the Nourishment grows unfit to be assimilated, or the central Earth grows too feeble to assimilate it, the Motion ends in Confusion, Putrefaction and Death.