The Kitāb al-iṣāba fī lawāzim al-kitāba (‘Book on the art of penmanship’, MS Berlin Sprenger 1918) attributed to Ibn al-Ǧazarī preserves a recipe (fols 14v-15r) that witnesses to a unique use of distillation for the preparation of an artificial golden ink.
Another one: on a golden coloured ink
Take one part of dissolved talc, two parts of honey, one part of qalqant and this is red vitriol—put everything in a vessel and whip it with the hand. Then put it into a ‘gourd’ or an alembic, and let it precipitate. Then put its precipitate into a long-necked flask, seal it for twenty days; then it will take on different colours, but be patient until it steadily takes on the colour of red gold, write with it and it will be beautiful.
اخر في حبر ذهبي اللون
يأخذ من الطلق المحلول جزأ ومن العسل جزؤين ومن القلقنت جزأ وهو زاج احمر واجعل الكل في ظرف واضربه باليد ثم اجعله في قرع وانبيق وقطره ثم اجعل قطارته في قارورة وختمه عشرين يوما فانه يتلون بالوان فاصبر حتى يثبت على لون الذهب الاحمر واكتب به فانه جيدا
The first step concerns the identification of the ingredients. The Arabic ṭalq may refer to a wide range of substances that look like a white powder. One may isolate two main groups of substances to which the term could refer: an inert mineral material or a slaked lime, which has an alkaline property.
The identification of qalqant is also problematic. The recipe itself has a specification about it—‘that is red vitriol’—which appears to be an addition to the recipe in the course of its transmission to explain an ambiguous or even obscure term. Red vitriol has been interpreted here as the result of the calcination (Figure 2) of green and blue vitriol (Figure 1), i.e. iron and copper sulphate.
The replication of this recipe consisted of the distillation of two different sets of ingredients: in one, honey and red vitriol were mixed with silica i.e. silicon dioxide (Figure 3) to represent an inert mineral substance; in the other, honey and red vitriol were mixed with slaked lime i.e. calcium hydroxide (Figure 4).
It was possible to obtain a distillate from both mixtures (with silica in Figure 5; with calcium hydroxide in Figure 6), both of which had the same colour, i.e. a pale yellow.
During the prescribed twenty days of ageing, both distillates progressively turned into a more intense shade of yellow-orange, settling at an almost brownish-orange after twenty days (Figures 7, 8), more intensely in the case of the mixture containing the silica (Figure 7). No further colour change could be observed after this period.
The ink prepared from the mixture containing silica resulted in an intense orange with a shiny metallic glance that, once dried, looked indeed like gold (Figure 9). By contrast, the ink prepared with the mixture containing slaked lime resulted in a brownish-yellow colour, still rather light, with a very faint metallic glance (Figure 10).