Weights and Measures

merchant thumbnail blog

(July 24th. Additions made; Jan 19th., 2014 – minor corrections; 6th. March, 2015 – header replaced; broken link replaced).

Some of these terms turn up in the Zibaldone da Canal, a fourteenth-century commonplace book or handbook which is filled with merchant-type maths problems – arithmetical mostly, but not so easy. There were different standards in each town, and different goods were offered by weight – as against volume.  The ‘ratl’ or ‘rotl’ measure of one town sometimes differing from another.  Some of the exercises he expects people to do using mental arithmetic I daresay would need pencil and paper now – if not a calculator.

The ‘dirham’ weight is the usual one in pharmaceutical and alchemical recipes.  Thanks to the kindness of the head of its holding library, I’m able to cite one of the alchemical recipes from that pharmacist-alchemist’s handlist from the Cairo geniza which I mentioned in an earlier post (because its dimensions were given as 225mm x 160mm).

Here it is (from private correspondence, so for invited readers only, I’m afraid identifying details omitted here):

An alchemical recipe for the production of silver. This recipe shows very close similarities to the tradition of Arabic alchemy linked to the 10th century Persian physician and alchemist Muhammad ibn Zakariyya al-Razi.

“Take the weight of 20 dirham of mercury, the weight of 10 dirham of horse manure, the weight of 5 dirham of non treated pearl, the weight of 10 dirham of white alum, the weight of 4 dirham of sulphurs and 5 dirham of [?]. Pulverize everything until it becomes a black powder. Put the powder in a flask previously isolated with clay and insert the flask in a “re made of manure. Then take it out and pulverize the content of the flask with some egg white […] put it in a flask covered with clay and light a “re under it from the early morning until the evening. Then extract what became of it: it is the white salt. Throw two dirham of this salt on “fty dirham of Copper or Lead [rasas – a bit rubbed]. It will give you silver, in God wants. This recipe works, it is true, if God wants”

Codicological details:

22.2 x 31.3 (15.7 one leaf); 28 lines

paper; 6 leaves (3 bifolia); holes, faded; 2 bifolia are badly torn

(To which my correspondent adds):

The dimensions you have are basically correct. Two of the bifolia are torn so that they no longer have their full width (see attached images*

We can’t say much more than that. It’s an oriental rag paper; the ink is probably a carbon-based ink, rather than iron-gall (it is blacker than it is brown and there’s no evidence of ink corrosion that I can see). The pages are crudely written, leaving almost no margin, no ruling or pricking, and the hand is one of these idiosyncratic hands that we seem to find on occasion (and which occur more commonly with mystical or alchemical texts?), which shows no real fluency (the script is square, but it’s not an accomplished hand by any means). It’s not the same hand across all the leaves. The hand on the intact bifolium is crude, but each letter has serifs, whereas the hand on the other leaves shows no serif, has a strange cross-like alef and is arguably more fluent, but still bad handwriting.

I would not like to estimate the date, since the hand is resistant to normal dating. Perhaps it belongs to a foreigner or someone who was not raised to write the Hebrew script as well as most Egyptian Jews were, or someone who does not normally write very often. Generally, given the paper, we’d say from 11th-13th c., being the ‘Classical Genizah period’, but it could conceivably be later. (Signature)

* – (not included in my blog- post  ~ D.)

So for merchants’ and pharmacists’ weights anywhere in Islam and regardless of whether in the work of a European or a resident of those regions,  ‘d[irham]’ or some other abbreviation might reasonably occur before or after a short-ish numeric series, supposing the text refers to recipes  as Baresch believed.

I’m adding the following address to add more of the terms used in medieval Cairo (and elsewhere) for measures of different goods.  Information on medieval Cairo – and presumably Alexandria – isn’t easily found.  Most of Canal’s trade was done in Tunis and Syria.  The link [updated, below] takes you to one page of a site filled with technical information about trade in medieval Islam – and when a web-article and glossary are provided with bibliography..  you know it has to be serious:




The project on that site is run by Professor Maya Shatzmiller, Western University, Ontario.  You can hunt by type of measures, region, and/or date range.

The link was formerly:

-x- http://www.medievalislamiceconomy.uwo.ca/measures-egypt.html




  1. I think we have a keyboard-interface problem here. For what appears as “re (sic) I think the original must have been fire. There was another seeming error which appeared as !ask(sic), and which I have corrected to flask.


  2. I’d love to know whether anyone’s tried using this recipe!

    Islamic metrology may not be central to the Voynich and its imagery, but it is actually something I know a little about. I would be extremely surprised if the dirham weight ever reached over 3.1g as suggested on the UWO website – numismatically I’m not aware of any evidence to support this, and particularly not from Egypt where silver was relatively scarce. Dirhams weren’t issued in Egypt in serious quantities until the Ayyubids and Mamluks, while gold dinars of the Abbasids, Tulunids and Ikhshidids are common..

    You might find this short article interesting:
    Rob has written extensively on metrology, and while his ideas aren’t universally accepted he is one of relatively few writers currently active in the field. If you’re really interested in this sort of thing, you might also look at http://www.academia.edu/3401823/Early_World_Coins_and_Early_Weight_Standards


    • Hello
      Thanks for the comment. I included this post only so that people working on the script might have an easy reference to check the text against weights used pharmacy beyond Europe.
      I don’t think many will be interested in a period earlier than the Mamluks; and I must say that for various reasons, the Khwarazmian Mamluks seem interesting here.

      Khwarazmian dynasty in Persia (1077–1231)
      Mamluk Sultanate (Delhi) (1206–1290)
      Mamluk Sultanate (Cairo) (1250–1517)
      Mamluk dynasty of Iraq (1704-1831, under Ottoman Iraq)

      What is often passed over in silence is that Mamluks were not Muslim by birth, but the children demanded as part of subjected nations’ annual tribute. Enlavement of any Muslim by another was prohibited by Islamic law. The practice of demanding tribute in both human and other goods seems to hark back to Egyptian times.


  3. By ‘Mamluk’ I think most people would only mean the Bahri and Burji Mamluks who ruled (consecutively) in Egypt. The other three aren’t normally called ‘Mamluk’, at least not in my experience (and not by Bosworth, for example), although they may did have slaves as founders – but then so did some other dynasties, come to that.

    Certainly the website on weights and measures you reference is concerned with Egypt, which is not surprising as much of our metrological data comes from glass weights and vessel stamps produced there. There’s much less of this sort of thing from the Muslim East.

    The Egyptian mamluks were bought, not claimed as a tribute. I have no idea at what point in their careers they will have converted to Islam, but like previous dynasties they seem to have derived their secular authority from the caliph of the day, so they must at least have converted by the time they received his seal of approval. And some, at least, seem to have become sultan in their early teens. My guess would be that they converted to Islam pretty soon after they acquired Muslim masters, but I’m embarrassed to say that I don’t know the answer to that one!


    • SirHubert.
      I think, that in practice, people probably just used offical weights, or lacking a set placed on their scales whatever dirham was in local circulation. As the Zibaldone da Canal makes clear, different cities had greater or lesser standard measures.

      But the point is peripheral, since the post is only here as a handy reference: a glossary of terms that may be of use to people working on the written part of the text.

      I don’t really want to argue about historical details, especially about discrepancies between eastern and western, or between official histories and items of documentary evidence, since this is not part of any historical argument about the Voynich manuscript.

      However, your cited sources notwithstanding, Islamic histories do include others than the Egyptian dynasties among Mamluks, and documentary evidence is unequivocal about children being demanded in annual tribute – not during the later period, but during the earlier.

      It is an unpalatable truth, and one of those normally deemed unmentionable. Of these (as I’m sure you know) medieval history contains not a few.


  4. We’re slightly at cross-purposes, I think. There were most certainly Mamluks, in the sense of military slave commanders, long before the Mamluk dynasties in Egypt. From memory, I think they were introduced under al-Mutawakkil (232-247h) around the time that the court moved to Samarra. But in terms of actual dynasties of Mamluks, in the sense that one Mamluk succeeded another, I think we’re still really looking at the Egyptian ones only.

    Strictly speaking, the Egyptian Mamluk Sultanate could not be passed by descent. This didn’t stop some sultans trying to found dynasties and appointing their children to succeed them, but I don’t think any of these attempts lasted beyond the two generations of father and son. Not that this need be any less stable or successful than a hereditary Sultanate – think of the Roman adoptive emperors of the second century.

    This wasn’t the case with the Khwarezmshahs. Anushtegin himself, the founder of the dynasty, was a slave and I’m sure that the mediaeval histories refer to him personally as a mamluk or ghulam. But he was succeeded by his son, who wasn’t a Mamluk or any other kind of slave, and whose name includes the Arabic Muhammad among Turkic elements. Descendants of Anushtegin, none of them Mamluks by definition, ruled in Khwarezm for some five or six generations.

    The main reason I’m writing so much about this is through my own ignorance – it simply hadn’t occurred to me (until you pointed it out) that practices of slavery prevented the son of a Bahri or Burji Mamluk from succeeding his father. Completely unrelated to the Voynich (well, probably, although the Mamluks were very much in control of Egypt in the early fifteenth century AD) but very interesting!


  5. I’d be very interested to hear about any similarities you might notice between imagery in the Voynich astronomical-meteorological sections and extant works from Khwarazm. Earlier rather than later, I think, because the dominant character is still early Hellenistic rather than Islamic. I don’t think that it can be reasonably attributed simply to al-Tusi.


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