ber, that neither my hands nor my estate
(though I had a thousand times more then I have) could ever suffice for
all. So that according as I shall hereafter have conveniency to make
more or fewer of them, I shall also advance more or lesse in the
knowledge of Nature, which I hop'd I should make known by the Treatise
which I had written; and therein so clearly shew the benefit which the
Publick may receive thereby, that I should oblige all those in general
who desire the good of Mankinde; that is to say, all those who are
indeed vertuous, (and not so seemingly, or by opinion only) aswell to
communicate such experiments as they have already made, as to help me in
the enquiry of those which are to be made.

But since that time, other reasons have made me alter my opinion, and
think that I truly ought to continue to write of all those things which
I judg'd of any importance, according as I should discover the truth of
them, and take the same care, as if I were to print them; as well that I
might have so much the more occasion throughly to examine them; as
without doubt, we always look more narrowly to what we offer to the
publick view, then to what we compose onely for our own use: and
oftentimes the same things which seemed true to me when I first
conceived them, appear'd afterwards false to me, when I was committing
them to paper: as also that I might lose no occasion of benefiting the
Publick, if I were able, and that if my Writings were of any value,
those to whose hands they should come after my death, might to make what
use of them they think fit.

But that I ought not any wayes to consent that they should be published
during my life; That neither the opposition and controversies, whereto
perhaps they might be obnoxious, nor even the reputation whatsoever it
were, which they might acquire me, might give me any occasion of
mispending the time I had design'd to employ for my instruction; for
although it be true that every Man is oblig'd to procure, as much as in
him lies, the good of others; and that to be profitable to no body, is
properly to be good for nothing: Yet it's as true, that our care ought
to reach beyond the present time; and that it were good to omit those
things which might perhaps conduce to the benefit of those who are
alive, when our designe is, to doe others which shall prove farr more
advantagious to our posterity; As indeed I desire it may be known that
the little I have learnt hitherto, is almost