, &c.
together with a thousand other obvious Instances of the changes of colours.
Nor have I _much_ medled with those familiar Phaenomena wherein man is not
an Idle spectator; such as the Greenness produc'd by salt in Beef much
powder'd, and the Redness produc'd in the shells of Lobsters upon the
boyling of those fishes; For I was willing to leave the _gathering_ of
_Observations_ to those that have not the Opportunity to _make
Experiments_. And for the same Reasons, among others, I did purposly omit
the Lucriferous practise of Trades-men about colours; as the ways of
making Pigments, of Bleanching wax, of dying Scarlet, &c. though to divers
of them I be not a stranger, and of some I have myself made Tryall.

Next; I did purposely pass by divers Experiments of other Writers that I
had made Tryall of (and that not without registring some of their Events)
unless I could some way or other improve them, because I wanted leasure to
insert them, and had thoughts of prosecuting the work once begun of laying
together those I had examin'd by themselves in case of my not being
prevented by others diligence. So that there remains not a little, among
the things that are already published, to imploy those that have a mind to
exercise themselves in repeating and examining them. And I will not
undertake, that _none_ of the things deliver'd, ev'n in this Treatise,
though never so faithfully set down, may not prove to be thus farr of this
Sort, as to afford the Curious somewhat to add about them. For I remember
that I have somewhere in the Book it self acknowledged, that having written
it by snatches, partly in the Counntrey, and partly at unseasonable times
of the year, when the want of fit Instruments, and of a competent variety
of flowers, salts, Pigments, and other materials made me leave some of the
following Experiments, (especialy those about Emphatical Colours) far more
unfinish'd than they should have been, if it had been as easie for me to
_supply_ what was wanting to compleat them, as to _discern_. Thirdly to
avoyd discouraging the young Gentleman I call Pyrophilus, whom the less
Familiar, and more Laborious operations of Chymistry would probably have
frighted, I purposely declin'd in what I writ to him, the setting down any
Number of such Chymicall Experiments, as, by being very elaborate or
tedious, would either require much skill, or exercise his patience. And yet
that this sort of Experiments is exceedingly Numerous, and mi