else, if there were no difference in their productions, every Creature would be alike, when as yet there are seldom two that do exactly resemble each other. But I desire you to understand me well, _Madam_, when I speak of Particular heats, colds, droughts, and moistures; for I do not believe that all Creatures are made out of the four Elements, no more, then that the Elements are produced from other Creatures, for the Matter of all Creatures is but one and the same; but although the Matter is the same, nevertheless, the Tempers, compositions, Productions, Motions, &c. of particular Creatures, may be different, which is the cause of their different exterior figures, or shapes, as also of their different Interiour Natures, Qualities, Properties, and the like. And so, to conclude, there is no impossibility or absurdity in affirming, that there may be Air, Fire, and Water, in the bowels of the Earth proper for those Creatures, which are in her, although not such an Elemental Air, Fire and Water, as is subject here to our senses; but another kind of Air, Fire and Water, different from those. But this being a subject for Learned and Ingenious men to work and contemplate upon, better, perhaps, then I can do, I will leave it to them, and so remain, Madam, _Your constant Friend,_ _and faithful Servant._ X. _MADAM,_ Your _Author_ mentioning in his Works, several Seeds of several Creatures, makes me express my opinion thus in short concerning this Subject: Several Seeds seem to me no otherwise then several Humours, or several Elements, or several other Creatures made of one and the same Matter, that produce one thing out of another, and the barrenness of seeds proceeds either from the irregularity of their natural motions, or from their unaptness or unactivity of producing. But it is to be observed, _Madam_, that not every thing doth produce always its like, but one and the same thing, or one and the same Creature, hath many various and different productions; for sometimes Vegetables do produce Animals, Animals produce Minerals, Minerals produce Elements, and Elements again Minerals, and so forth: for proof I will bring but a mean and common example. Do not Animals produce Stones, some in one, and some in another part of their bodies, as some in the Heart, some in the Stomack, some in the Head, some in the Gall, some in the Kidnies, and some in the Bladder? I do not say, that this Generation of Stone is made the same way as the natural generation of Animals, as, for example, Man is born of his Parents; but I speak of the generation or production of Creatures in general, for otherwise all Creatures would be alike, if all generations were after one and the same manner and way. Likewise do not Fruits, Roots, Flowers and Herbs, produce Worms? And do not Stones produce Fire? witness the Flint. And doth not Earth produce Metal? 'Tis true, some talk of the seed of Metals, but who with all his diligent observations could find it out as yet? Wherefore it