Barrow, John [Hrsg.]: Dictionarium Polygraphicum: Or, The Whole Body of Arts Regularly Digested: Illustrated with Fifty-six Copper-Plates. In Two Volumes (Band 1) (London, 1758)

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Therij having made clean a copper that will hold a tun of
water, put into it two pounds of madder, two pounds of bran,
and two pounds of pot-afhes ; boil them a little, and let them
fettle, and pour the indigo upon them ; then drain the ley alfo
into the vat, but the indigo, efpecially, muft be digefted very well
and diflblved, and the copper filled with water, covered clofe,
and a fire made under it; fuffer it to grow warm, but not hot,
ftirring it about every two hours, till it ferments; and, as foon
as it begins to melt or digeft, it will alfo begin to turn yel-
Jowifhj and then you may dye with it, taking care that your
hands are very clean, and free from all forts of greafe.

When you have dyed v/ith the fuds, you muff, ftrengthen
them afrefh with pot-afhes ; but you muft take care to do this
neither too much nor too little ; for, if you are guilty of either
extreme, the whole copperful of ley is fpoiled.

Neither ought you to dye too often at one time ; but, betwixt
every time you dye, the liquor muft be very well ftirred.

An excellent liquor to make the Blue fuds work, in cafe it
happens that they will not, by reafon of fome defect. Take
four ounces of madder, four ounces of pot-afties, and two hand-
fuls of bran ; boil them together, and pour the liquor into the
Blue fuds ; {fir it well about, and it will make it work ; and, if
it be too much fattened with afhes, then hang a bag of wheat
flour in it, and that will attract all the fatnefs to it; and, if it be
yet defective in any particular, add to it a fmall quantity of falt-
petre, and that will bring it to; a fermentation, as will alfo a
little grounds of beer, which indeed is one of the beft remedies.

Blue Japan. Take gum water, what quantity you pleafe,
and white-lead a fufficient quantity ; grind them well upon a
porphyry. Then take ifing-glafs fize, what quantity you pleafe;
of the fined: and beft fmalt, a fufficient quantity ; mix them
well; to which add of your white-lead, before ground, fo much
as may give it a fufficient body ; mix thefe together to the con-
fidence of paint.

With this mixture do over your work, and repeat this three
or four times, till you fee your Blue lies with a good fair body,
letting it dry thoroughly between each time ; if the Blue be too
pale, put in more fmalt into the fize, without any white-lead.

Then rub it very fmooth, and go over it again with a
ftronger Blue ; and, when it is thoroughly dry, walh it twice
ever with the cleareft ifing-glafs fize alone ; cover it, and let
it dry two days.

Then warm the piece gently before the fire, and with a clean
pencil wafh your work over with the fined: white varnifh, re-
peating it feven or eight times, and let it dry two days, as be-
fore ;