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Hooke, Robert, 1635-1703

"Micrographia Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon"


The way, in short, as I received it from the _Learned Physitian Doctor_
I.G. is this;
Reduce the Metal you would thus shape, into exceeding fine filings, the
finer the filings are, the finer will the Balls be: _Stratifie_ these
filings with the fine and well dryed powder of quick Lime in a _Crucible_
proportioned to the quantity you intend to make: When you have thus filled
your _Crucible_, by continual _stratifications_ of the filings and powder,
so that, as neer as may be, no one of the filings may touch another, place
the _Crucible_ in a _gradual fire_, and by degrees let it be brought to a
heat big enough to make all the filings, that are mixt with the quick Lime,
to melt, and no more; for if the fire be too hot, many of these filings
will joyn and run together; whereas if the heat be proportioned, upon
washing the Lime-dust in fair Water, all those small filings of the Metal
will subside to the bottom in a most curious powder, consisting all of
exactly round _Globules_, which, if it be very fine, is very excellent to
make Hour-glasses of.
Now though quick Lime be the powder that this direction makes choice of,
yet I doubt not, but that there may be much more convenient ones found out,
one of which I have made tryal of, and found very effectual; and were it
not for discovering, by the mentioning of it, another Secret, which I am
not free to impart, I should have here inserted it.


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