One of the difficulties as a re-enactor or a historian, is how seriously to take a picture in an original manuscript. This is especially with regards to clothing, since plant dyes generally produce different shades from mineral based manuscript colours and people may not be portrayed wearing up to date fashionable clothing, because they are meant to be ancient Biblical characters.
Regarding Alchemy and the history of science and technology and material stuff, this well known illustration from Thomas Norton is interesting:
This is one of the late 15th century illustrations for Thomas Norton’s Ordinal of Alchemy. The seated figure is wearing an open fronted doublet of late 15th century sort, with a gown and rather flat fronted shoes, all suggesting late 1480’s or 90’s.
On the table in front of him is a glass cased balance, the first known illustration of a scientific balance, that is one isolated in a glass case to allow for more accurate weighing.
Below the table is a chest, bound with iron, a lock on the front and with a curved lid.
This matches the sort of chest used in the later medieval period for transporting goods and valuables. Although no handles are visible, the lockplate design seems accurate enough, as of course is the fact it is bound with iron and with the rounded lid (perhaps to shed water better when being transported on a cart), it looks a bit like this surviving example:

Although the Norton one is clearly a lot smaller than the 51 inch wide circa 1500 church chest. Yet given the sort of variations in those which have survived, and how limited a selection of boxes and chests we have, I have no hesitation in saying that the one in the Norton illustration is entirely acceptable for use if re-created.

The alchemical operations and furnaces shown in this and other illustrations deserve a post all on their own. As does the glassware. But I thought it was interesting that real examples of chests like the one in the illustration have survived. We can’t say that for many medieval things beyond the pottery and copper alloy objects. On the other hand by using knowledge of different areas of medieval material culture we can securely date the picture.
(medieval cloth is annoying me, simply because we have so few examples that it is hard to tell exactly what the different sorts were used for)

But looking again at the illustration, the contents of the chest are rather mysterious. Many historians seem to accept them as being cupels, that is, nearly cylindrical objects made of bone and wood ash. They are used for cupellation of precious metals, that is, reacting the metals with lead in a furnace to see how much gold or silver is present in the sample. Which is of obvious interest to an alchemist, but why show them in the chest itself? I don’t know, except I do wonder if they really are cupels, and instead are crucibles. You can see that there are different colours within them, which could represent the four elements (held safely within the chest) or substances to be worked on. The view that they are crucibles is also that of Newman and Principe, in “Alchemy tried in the fire”, but I disagree with them when they suggest that the gold coloured object inbetween the crucibles may be a monk and former to make the crucibles. Yet it is clearly not of the same size as the crucibles, and overly complex – even in this poor quality reproduction you can clearly see that the golden object looks more like a cup with lid.

So what? I hear you cry.
Well, if it isn’t an item for making crucibles, then Newman and Principe are wrong, but also the question is, what might it be? This is where I get a little less secure. Norton’s illustrations are clearly a mixture of realistic objects and ideas/ ideals. For instance in another of the illustrations the illustrious alchemists Geber, Arnald of Villanova, Rasis and Hermes watching alchemical operations being carried out and commenting on them. Thus they are a mixture of the practical and the esoterically meaningful.

So in this case, struck by the shape, I propose that it is intended as a pyx or ciborium. This was a decorated cup with lid used to hold the wafers before and after the eucharist. Hence it’s value, and why it is kept in an iron bound chest. Of course to modern sensibilities that sounds a little blasphemous. But Norton wrote: “For it is most profunde philosophie, The subtile science of holie Alchmymye”; and later he insists that the alchemist must have grace to be successful. Certainly these were orthodox protestations at the time, but remember also that for several generations now alchemists had been drawing parallels between the properties of the stone and the resurrection of Christ. Other similar objects with similar meanings are pyxs and Chalices, which I am sure you will have hear of.

Newman and Principe would likely have been misled by a 17th century rendering of the same drawing, which clearly shows the central object in the chest as being the same size as the crucibles, and without a foot. Thus the importance of going back to the originals!
And what of the other things on the table? I think we all agree that they are a silver crescent moon, a golden, circular sun, and a more complex object of mysterious purpose. Newman and Principe suggest it is a former for making cupels. This fits with their general line of argument about the importance of weighing and measuring in both alchemy and cupellation of the period. Again, this is understandable given the poorer quality 17th century illustration, but I disagree, because in the original illustration it looks more like a jar of jam with a cloth cover over it held in place by an elastic band around the rim. Which is nothing like something used to make a cupel. They suggest that the frill around it is a spume of lead similar to that emitted when actually doing cupellation of precious metal, as the lead liqufies and evaporates.
Well, that only makes sense if you think within their particular paradigm. When you step outside it, and try to think more like a medieval person, it makes less sense. Quite apart from the frill of metal starting part way down the side of the vessel, which means it has a lid, and you don’t have a lid on a cupel it has to be open to the air to oxidise the metals, there is the question of its golden colour, which again isn’t exactly a property of a complete cupel.

I don’t know what it could be; deciphering the words around Norton’s head might help, but they are difficult to read and I haven’t found a copy of them yet. Or else I’ll have to read more of the Ordinal.
But this should also serve as a warning about getting too caught up in your own pradigm. That of Newman and Principe is to concentrate on the physical real alchemy and concrete things like cuppellation, and ignore as much as possible the difficult and dangerous question of allusions and meanings that drove so much of alchemy and indeed human life.

Edited to add this picture of the Lacock chalice, a 15th century covered chalice, with which you can play spot the difference: