Searching through the Ferguson Collection in Glasgow has been interesting, and turned up a variety of manuscripts related to my interests. Okay, some are in Italian, or are illegible, but still they are worth a look, and others, like the version of Norton’s Ordinal, have nice pictures.
One especially useful is a 15th century one that has many alchemical recipes written in English. Thus I can understand them quite well. It is MS 205, and the catalogue says it is a liber de consideratione quinte esentie ervici rerum transmutabili in latin, Xvth century, but it is so much more than that. There is some Lull of course, Albertus and Dekyngstone, the latter which proves it is of English origin.
There are also marginal notes, not always of any use but interesting to see what a later reader was interested in.
It turns out that someone else has already studied it:
I shall endeavour to get a copy of her thesis. It would save a lot of work, and the wear and tear from me reading the original copy enough times to actually understand it. Meanwhile, I am still learning to read the handwriting, although I am much better at it than I was 8 years ago when I first started looking at original manuscripts. The spelling doesn’t help too.
The recipe I am trying out, from f81v, goes:
“Then if you will make silver of thy lead, hammer it small and put thereto 3 parts clean powder of alum y calcyned, and medle thaym both together and then take potters clay and medle thereto with as a man medleth spices to paste, and gather all up and torne hit and knede hit thriftily to the day and make it as a balle, and thene dry it and then llor the have a potte to pirpes or /??? comym down and in ?? fidge of the ?? and put thy ball therein, and make there under a store size and lete it melt down by the ??? of the muffle(?!!! reference to a muffle furnace/?) and the pipes in the bottom and thene lyumell hit again and do therewith as the did before and do this t and if thy have any portion of the arsenic afore ??? medle perche or mercury sublimed and there shall come there of fyne silver.”
It basically looks like a method for purifying lead in some way or another, yet with the chance to add some impurities to it, I.e. whatever might dissolve into the lead.
So I started on the first part of it at Traquair, putting burnt alum and lead together into a ball. It didn’t dry very well and started exploding, what the recipe doesn’t mention is how long to leave it to dry for. Oddly enough an hour at a gentle heat isn’t enough. As you can also see from the photo below there wasn’t much of a reaction between the alum and lead, although the former baked together a bit more before the lead actually melted, possibly due to moisture from the clay.
The final part, using sublimed mercury or arsenic is a more usual way of whitening copper, not lead, but of course a lead-arsenic alloy would be quite white and shiny. Still have a lower melting point than silver, but the main issue would I think be it’s softness.
I’m curious as to how this will turn out after the lead has been melted through the alum a few times, so I shall repeat it some more with a new ball of clay and lead.
I haven’t seen a recipe quite like this before, but the funny thing is that I have seen burnt alum used a few times in the manufacture of acids. Not for whitening or purifying lead at all. Moreover, as is usual in this sort of recipe, no theory is given in this part as to why you do things this way. The Summa Perfectionis says to mix lead with filings, alums salts and glasses, for purification, and also the water of alums. Perhaps the MS205 recipe comes from a comment in chapter 4 of book 2 of the Summa, which from Russell says, calcination is important, and alums harden jupiter, although how is not clear, and Saturn is calcined with the acuity of salt. But always I am worried that alum might mean something not alum at all…