And though of late, men, beginning to be sensible of this convenience, have here and there registred and printed some few _Centuries_, yet for the most part they are set down very lamely and imperfectly, and, I fear, many times not so truly, they seeming, several of them, to be design’d more for _Ostentation_ then _publique use_: For, not to instance, that they do, for the most part, omit those Experiences they have made, wherein their Patients have miscarried, it is very easie to be perceiv’d, that they do all along _hyperbolically extol_ their own Prescriptions, and vilifie those of others. Notwithstanding all which, these kinds of Histories are generally esteem’d useful, even to the ablest Physitian. What may not be expected from the _rational_ or _deductive Faculty_ that is furnisht with such _Materials_, and those so readily _adapted_, and rang’d for use, that in a moment, as ’twere, thousands of Instances, serving for the _illustration_, _determination_, or _invention_, of almost any inquiry, may be _represented_ even to the sight? How neer the nature of _Axioms_ must all those _Propositions_ be which are examin’d before so many _Witnesses_? And how difficult will it be for any, though never so subtil an error in Philosophy, to _scape_ from being discover’d, after it has indur’d the _touch_, and so many other _tryals_? What kind of mechanical way, and physical invention also is there requir’d that might not this way be found out? The _Invention_ of a way to find the _Longitude_ of places is easily perform’d, and that to as great _perfection_ as is desir’d, or to at great an _accurateness_ as the _Latitude_ of places can be found at Sea; and perhaps yet also to a greater certainty then that has been hitherto found, as I shall very speedily freely manifest to the world. The way of _flying_ in the Air seems principally unpracticable, by reason of the _want of strength_ in _humane muscles_; if therefore that could be suppli’d, it were, I think, easie to make twenty contrivances to perform the office of _Wings_: What Attempts also I have made for the supplying that Defect, and my successes therein, which, I think, are wholly new, and not inconsiderable, I shall in another place relate. ’Tis not unlikely also, but that _Chymists_, if they followed this method, might find out their so much sought for _Alkahest_. What an _universal Menstruum_, which dissolves all sorts of _Sulphureous Bodies_, I have discover’d (which has not been before taken notice of as such) I have shewn in the sixteenth Observation.