What the lute on the outside of my cucurbit looks like after it has been used a few times



The lute on my cucurbit started to come off after being knocked, so here it is in bits:cucurbit lute side viewinside of cucurbit lute piece

That it comes off after being hit is fine by me, acting as a sacrificial coating is a good thing. As you can see it was made using iron rich clay, also horse dung and sand. The mixture used was made up by feel, rather than following any particular proportional recipe, with the key ideas that it had to be able to be smoothed onto the cucurbit, yet with sufficient sand and dung to hold together when drying.

Unsurprisingly, because the general recipe is the same as medieval bronze casting moulds, it looks very much like medieval mould material that I have examined, except that a lot of that often contained chaff or bits of straw as the organic material, rather than dung.

Here’s something else, a wide flat graphite crucible, meant more as a nice open bowl like a scorifier, and for a similar purpose, i.e. oxidising substances over a fire.

graphite crucible with bottom broken due to not being dry enough

Unfortunately in this case I didn’t dry it for long enough in my oven. It had a wee while, but not enough, so when I put it on the fire to be properly fired, the bottom popped off due to residual internal moisture turning to steam and expanding.

A note on the alleged alchemist Nicholas Flamel



Many of you will have heard of Nicolas Flamel, a late 14th/ early 15th century French Parisian alchemist. Except he wasn’t an alchemist, and was dreamt up as one in the 17th century, by a couple of Frenchmen who wanted an indigenous famous alchemist and give alchemy better historical depth than they thought it had.

Nevertheless, I am sure that lots of people will continue to think he was, going by vague memories of information picked up from various sources, such as the Harry Potter series.

Anyway, some of an interesting account of his life is available on google books:


It seems that Flamel was a scribe, married a richer older widow, used her money in a lifetime of cunning property based transactions (buying, renting out, selling) to amass an impressive fortune. Alchemy doesn’t come into it at all, for more information on that, see Nigel Wilkins book Nicolas Flamel Des livres et de l’or.

The problem is of course that the idea that Flamel was a genuine medieval alchemist is already well embedded, in popular and esoteric culture. I suggest that the best thing to be done is simply flood the culture and popular mind with real, good histories of alchemy, in which the Flamel myth is mentioned as appropriate as part of early 17th century cultural shenanigans. That way people will learn only the real history of alchemy.

I have read that evidence shows that repeating a falsehood and then debunking it tends to cement the falsehood in people’s minds as being true. (Naturally I don’t suffer from that…) Therefore often the best thing to do is just flood it out with better information about a topic, but without mentioning the actual falsehood, so next time someone thinks of knights on horseback, they think of charges or jousting, not of cranes and winches, which is a Victorian myth that might come from some comedy book.

That at least is the theory. Lacking a Murdochian control of the world’s media, it is unlikely that I’ll ever get to try it.

Strange bright yellow stuff turned up in the ash of my firebox



I don’t know what it is. The ash had a yellow tinge to it, and when I used it to try and make KOH it left me with this bright yellow solution. Funky colour, shame I don’t know what causes it.

Odd yellow liquid from ashes

It is likely a water soluble oxide of some sort; when I had an accidental fire last year some plastic and an old paint can with paint in it got burnt, and plastic often has metallic compounds in it to give colour and make it more light resistant. Metal compounds used include iron, barium, antimony, lead, nickel, chromium. Some of these aren’t very nice, so this is one substance I definitely won’t be tasting.

The analytical problem is that to carry out a simple flame test the potassium and sodium of the ash would probably mask any other colour present, since they are there in such quantities and give such bright flames.

One thing to try was to neutralise the KOH and CaOH present by the addition of vinegar, and see what that did to the colour. I took a sample and added acetic acid, it foamed and bubbled nicely, and the solution cleared slightly, but is still bright yellow. Now to work out how to separate the substances that are in solution.

Dyeing cloth with indigo is very hard


I’ve been messing about with dyes a few times now, and thought I could try woad, which was popular in the medieval and post-medieval period for dyeing cloth blue, or using it with other dyes to get green or black or suchlike.

Unfortunately, getting hold of woad leaves is tricky and expensive, it is easier to try with the (chemically identical to the historical stuff) indigo pigment you can buy in powder form. Unfortunately the preparation method is simple, yet difficult to make work, because it relies on having a pH of around 9 and a lack of oxygen in the water bath. I was roughly following the method in “Colours from nature” by Jenny Dean, but right at the start it didn’t work, since the instructions to mix indigo powder and washing soda (Sodium carbonate) in hot water just didn’t happen, insofar as the indigo stayed as gritty lumps.

indigo not dissolving

Continue reading

Making Salt of Urine


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Or, How to lose friends and make enemies

The downside of following authentic alchemical recipes is that, even although they are safe enough, some of them stink.
So it is with salt of urine.

The Kitab-al-Asrar of Ar Rhazi, the famous Arabic physician and alchemist has a recipe for making salt of urine. It says to take 10 litres of urine, leave it in the sun for 40 days until it becomes solid, or else put it in a fire until it becomes solid.
As you would expect there is an ammonia like smell to it. The recipe says you can let it become solid in hot ashes.
Possibly I botched this recipe a little, because I had a black substance when I had boiled all the moisture away:
Salt of urine before blowtorchJPG

By the way, the horrible bubbling black stuff from that video a couple of weeks ago is this experiment. Continue reading

A short video of heating alum


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The Libellus de Alchemia, by pseudo-Albertus Magnus (Sister Virginia Heines translation) has a short chapter on the preparation of alum to be used in the alchemical work. All you do is put it in a crucible and stick it in a furnace, heating slowly at first then afterwards strongly and allow it to dry through a day at full heat. When cool remove it, it’ll be snow-white and is used for making the liquid for whitening.

Obviously I can’t stick a camera inside a furnace. The recipe is a little unhelpful as well as to the temperature, but since it describes the building of a wind or natural draft furnace in some detail atthe start, you must expect temperatures of over 900C.
Which can be reproduced by a blowtorch, hence this video:

Note that thanks to the large amount of water locked up in the crystals with the metal sulphates it melts first, before the water boils away.
The white stuff is the puffed up mixture of potassium sulphate and aluminium sulphate, although it is likely that since the aluminium sulphate breaks up around 700C, it’s a mixture of aluminium and potassium sulphate, which melts at 1069C, a temperature my blowtorch won’t really reach, or rather, despite the flame temperature being higher than that, it isn’t putting enough heat into what it hits to be able to melt anything that melts at that temp.
Anyway, that’s what happens when you make your snow white calcined alum.

Now in modern times we know alum is useful as a fire retardant, but beyond some ancient Greek mentions I haven’t found anything about it being so used in medieval Europe.

Is there much evidence for direct master- pupil transmission of alchemical knowledge in the 13th to 16th centuries, and how much did initiation matter versus learning from books?


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The first part of the title was sparked by reading a blog on Antonio Neri which mentioned schools of alchemy, and of course I started to wonder how much evidence there was for the transmission methods of alchemy. The second part is something I’ve been wondering about for a while.

So of course I started reading, and the answer is of course, yes, there’s plenty of evidence if you accept what the alchemists themselves wrote.

Which is a bit of a problem, insofar as their texts were written for so many different reasons and audiences and in most cases we just do not have other evidence of any use. The earliest alchemical text, the Physika et Mystika contains a story about the transmission of alchemical knowledge, but even there the story is complicated. The master dies suddenly, seemingly without transmitting the final secret to his son or his disciples. Eventually they have a feast in a temple in his honour, and during it a column splits open to reveal some books and these turn out to have the useful information and the saying “Nature delights in nature, nature conquers nature, nature masters nature.”

So books are important, but so also is initiation in a father – son relationship.

Another reason for looking at this topic is that modern esotericists have a similarly complex relationship to knowledge transmission, and some like to harp on about the initiatory part and how they learnt the secret from a master, others are clearly working from texts, and it is interesting to see whether or not their practise is much different from that of 600 years ago. I can’t find much information about the varying transmission routes in historical periods either, at least not gathered together in one place. So, on with the findings:
Continue reading


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