Cold extraction of mercury with lead, tin & iron

For an introduction to the recipes that have been replicated, see the section Cold Extraction of Mercury: Sources

Syriac recipe

Anonymous, Ninth book (Syriac alchemical collection, MSS British Library, Egerton 709 and Oriental 1593)

(Another) recipe: take a lead mortar and put cinnabar in it; then, grind it in water with a pestle comprised of lead, until quicksilver is produced. (Another) recipe: add vinegar and grind (cinnabar) in the sun.

ܣܝܪ. ܣܒ ܡܕܟܬܐ ܘܕܩܘܩܐ ܕܟܘܢ ܘܐܪܡܐ ܒܗ̇ ܩܝܢܒܪܝܣ ܘܫܚܘܩ ܒܡܝ̈ܐ ܥܕܡܐ ܕܗܘ̇ܐ ܗܕܘܪܘܪ ܓܘܪܘܢ. ܣܝܪ. ܐܚܪ̈ܢܐ ܕܝܢ ܚܠܐ ܪܡܝܢ ܘܫܚܩܝܢ ܒܫܡܫܐ

Greek recipe

Zosimus of Panopolis (Greek tradition), Chapters to Eusebeia

I think that it is better to grind cinnabar […]. In fact, different substances produce quicksilver (lit. cloud) when they are processed with water or vinegar in the sun. And we know this from experience. And every book as well as Chymes and Maria say: “Lead mortar and lead pestle. Grind cinnabar with vinegar in the sun until quicksilver (lit. cloud) is produced”. They do the same with tin (mortars and pestles).

ἐγωγε νομίζω βέλτιον εἶναι κιννάβαριν συλλειοῦν […]. Καὶ γὰρ οἰκονομούμενα ἐν τῷ ἡλίῳ τὰ εἴδη ὕδατι ἢ ὄξει νεφέλην ἀποτίκτουσιν· καὶ τοῦτο διὰ πείρας ἐπιστάμεθα. Καὶ πᾶσαι αἱ γραφαὶ καὶ Χίμης καὶ ἡ Μαρία φησίν· θυΐα μολιβδίνη καὶ δoίδυξ μολίβδινος· κιννάβαριν ὄξει λείου ἐν ἡλίῳ ἕως γένηται νεφέλη. Ὁμοίως καὶ ἐπὶ κασσιτέρου πάλιν τὸ αὐτό.

Replicating the procedure

With respect to the use of metals other than copper, the replications confirmed that lead can reduce mercury. Although the formation of a black powder (lead sulfide, PbS) can be observed, no droplets of mercury are visible due to the formation of a powdery HgPb amalgam (see figure 1).

When the reaction occurs with tin, the formation of the amalgam (HgSn) is clearly obtained, but the product of the oxidation of tin, probably tin sulfide, is hardly detectable. This amalgam (see figure 2), from which mercury can be easily recovered by heating, is a soft silvery paste, which ancient alchemists may have easily identified as being a kind of mercury.

Lead pellet ground with cinnabar
Fig. 1. Lead pellet ground with cinnabar
Tin powder ground with cinnabar
Fig. 2. Tin powder ground with cinnabar

As for iron, so far we have only detected a single recipe that instructs to add iron scrapings to be ground with cinnabar. In the Book on mercury, only preserved in Syriac translation (full title: Ninth treatise on the letter ṭet. The letter ṭet includes the full discourse that speaks about the work of mercury), Zosimus adds the following procedure

Another (recipe). Take pure leaves of iron and make use of a mortar. Make scrapings as it is explained above (in the section) on copper (leaves) or as it is explained by Pebichius , and (mercury) is produced.

ܣܝܕ. ܣܒ ܦ̈ܛܠܐ ܢܩ̈ܕܐ ܕܐܪܝܣ ܘܐܬܚܫܚ ܒܝܕܣܬܐ. ܥܿܒܕ ܕܝܢ ܫܘܦܐ ܐܝܟ ܕܐܡܝܪ ܡܢ ܠܥܠ ܥܠ ܐܦܪܘܕܝܛܝ ܐܘ ܐܝܟ ܕܐܡܝܪ ܠܗ ܠܦܝܒܝܟܝܘܣ ܘܗܘܐ

Zosimus seems to refer to another recipe where copper scrapings were ground with cinnabar, and, in a second phase, the mixture was heated in a closed vessel (see the second recipe in the section Cold Extraction of Mercury with Copper). It is worth noting that simply grinding iron does not cause a redox reaction. Only when cinnabar and iron are heated together in a closed vessel do they easily yield mercury. This procedure appears to have been known to the earliest alchemists, such as Pebichius, who lived in the first to second century CE (see Heating Cinnabar in a Closed Vessel with Iron).