(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”
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: