35 - Another Green, Which 'Carries the Palm' for All Other Greens, Made by Me
To a large crucible, add 10 pounds of glass, which is half crystallino, thrown in water several times, and half common white polverino glass [and fuse them]. Now take 4 pounds of common polverino frit, with this, mix in 3 pounds of red lead [lead oxide]. Unify them well and add them into the above crucible. In a few hours everything will have clarified, now purify it by throwing it in water. Inspect the glass carefully before returning it to the crucible.
All lead precipitating out of the glass must be removed with diligence, throwing it away, so that it does not make the bottom of the crucible break out, as can happen. Return the glass that was thrown in water to the crucible and leave it to clarify for a day. Then add the colour using the powder made by dry distillation of vitriol of copper [ copper sulfate] made chemically. Also, add a little crocus of iron, but very little. The result will be a most marvellous beautiful green, the best that I ever made. lt will seem just like an emerald of ancient oriental rock, and you can use it in every sort of job.