Take half an ounce of Roman vitriol, half an ounce of saltpetre, six pennyweights of salts of ammonia, half an ounce of verdigris, and pound them upon a stone, do not use iron. Pound the salts of ammonia first very carefully, then all the others together. Then mix them in a glazed vessel[188] with as much water as shall make them have the consistency of a sauce, stir them over the fire with a piece of wood, & let them boil for such space as you can say two Paternosters. Do not give them a strong fire for that would spoil them. Everything in moderation. Let them cool, and use them as is here written in the manner following.