don't work it with great care, no Pots nor Cruci∣bles will hold it, for it will crack them and run out. I will here give all the Methods of preparing it, and that so distinctly, that the unexperienced may succeed in it. The Business principally consists in knowing well how to calcine the Lead, and re∣calcine it again, which is commonly known, not∣withstanding in the next Chapter we will shew how to do it for the sake of those that do not know it. The better the Lead is calcined, the less apt it is to turn into Lead again, and break the Pots in this Operati∣on. We will also shew, that you must always drop the Glass into Water when it is melted, for the least Lead remaining in it, breaks out the bottoms of the Vessels, and s•• you lose your Matter, which may be avoided by carefully minding what we have said, and which we shall note again in the following Chap∣ters.
It is our Opinion, and that not without reason, that that subtilty whereby the Lead so easily in this case pierces the Pots when it is not wholly calcin'd, comes from a certain unctuous yellow Matter like Oyl, that is seen to swim on the top sometimes in a violent fusion. For we have often observed, That if that unctuous Matter be not taken off as soon as it ap∣pears on the top, it will pierce the Pot, and so all run out among the Coals.
This unctuous Matter has strange and infinite Vir∣tues known to the Adepti, both in curing Diseases, and other Operations. He who knows how to make it Transparent, and give it the Jacynth Colour in E∣zekiel, which is that Electrum spoken of in the first Chapter, may boast he has a Material, from which may be extracted a lac Virginis, in great esteem among the Philosophers. But let this suffice, we are not here to instruct the ignorant in those Arcana, but re∣mit them to the Writings of the Adepti.