_In the Fourth Part shall be taught another certain, and hitherto unknown Furnace, in which all Chymical Operations may most easily be done: being most profitable for the trying of the Natures of Minerals and Metals; as also for the proving, examining, melting, cupelling, and separating of Metals, that nothing may be lost of them, and that after a compendious and easie way, and also to great advantage._ _In the Fifth shall be taught how to make and prepare Iron, Earthen, Glass, and other kind of Instruments necessary for the aforesaid four Furnaces, as also other necessary, and most profitable Manuals._ _And in the First Part, the Fabrick of the first Furnace being delineated, I shall also shew how by the help thereof may be made Spirits, Oyls, Flowers, and other most profitable Medicaments, also their Vertues and Use, and that as faithfully as I may, and without fraud. And truly I do not doubt but those of understanding will approve of this Work, but ignorant =Zoilus’s= will contemn it: For it is said according to the Proverb, =He that builds by the highway, will hear many things from them that find fault=, and especially from the vulgar, =&c.= But it would be well if those =Thrasoes= would put forth something more excellent, before they find fault with and carp at other Mens pains and labours._ _Wherefore let no one rashly judge of this Work, untill he be throughly informed concerning the same, and then I do not doubt but the Authour shall be by him commended._ _And if haply all things shall not presently succeed well, to his mind, with him that shall build this Furnace, and operate therewith, let him think with himself that perhaps he hath erred in some part, (for it is a new and unknown work, in which any one may easily err) and not presently therefore murmur against the Authour, blaming him, because he hath not wrote clear enough, but let him ascribe it to his own ignorance, and let him study to understand the Authour’s meaning, and still be practising upon it, and then I do not doubt, but he will have better success, which I pray every one may have._ Amen. The EXPLICATION of the Figures of the first Furnace in all its parts. =FIG. I.= E. _The first Subliming-Pot, which is set into the upper hole of the Furnace._ D. _The upper hole of the Furnace._ F. _The second Pot._ G. _The third._ H. _The fourth._