Chapter XXXV · HOW TO MAKE AQUAFORTIS FOR PARTING.
C. R. (Charles Robert) Ashbee translation
Aquafortis for parting[198] is made thus. You take 8 lbs. of burnt rock alum[199] & an equal quantity of the best saltpetre, and 4 lbs. of Roman vitriol, & put them altogether into the alembic,[200] add to these things a little aquafortis that has already been used, exercising your discretion as to the quantity. And in order to give a good luting[201] to your alembic take horse-dung, iron filings & brick dust in equal proportions, and mix them up with the yolk of a hen’s egg, then smear the mixture over the alembic as far as the furnace will allow. Then for the rest put it to a moderate fire, as the wont is.
FOOTNOTES:
Notes in this chapter
Note 1 · Partire.Note 2 · Allume di rôcca arso. Prof. Church tells me that this is probably sulphate of alumina, from alum shale.Note 3 · Boccia. Biringoccio in the fourth book of his ‘Pirotechnica,’ Venice, 1540, Chap. I., gives an illustrated description both of such an alembNote 4 · Loto: the closing of the joints.