On making vermilion. If you wish to make the finest vermilion, take a glass jar and lute it outside with the finest clay, three times; and then take one weight of quicksilver and two weights of white or yellow sulphur, so that there will be two parts of sulphur and a third of quicksilver. And put in the above-mentioned ingredients in such a way that part of the sulphur, finely divided, may be on the bottom, and part of the quicksilver above, so that it may reach right up to the neck of the jar. Put the jar upon four stones, and then build up a charcoal fire around the jar, but let it be a very moderate one. And so cover the mouth of the jar with a little tile or piece of stone. And when you see that the smoke is blue or yellow coloured, as it comes off, put on the cover; and when you see that the smoke is almost as red as vermilion, take it from the fire, and you will have in the jar the finest vermilion.