sulphate of indigo, Prussian blue (blu kiyāns), Chinese blue (čā’is blu)

Ingredients

sulphate of indigo, Prussian blue, oxalic acid, rainwater, distilled water, Chinese blue, chalk, powdered black ink, iron sulphate, gum Arabic, sulphuric acid

Preparation Steps

Original Recipe Text

Hosseini lists five blue ink recipes (p. 169-170). R1: 3 ounces sulphate of indigo in 1 gallon water, added to 2 ounces common Prussian blue and 1 ounce oxalic acid; Prussian blue is washed with rainwater (p. 169). R2: 2 ounces Chinese blue and 1 ounce oxalic acid in preboiled warm water (p. 169). R3: Sulphate of indigo in water, with chalk added for a lighter shade (p. 169). R4: 2 parts powdered black ink, 2 parts iron sulphate, and 1 part gum Arabic are beaten into a powder (p. 170). R5: Prussian blue is dipped in strong sulphuric acid, washed, dried, and then soaked in oxalic acid and water (p. 170).

Evidence

"The first underlined word in the recipe reads “blu kiyāns” which is most likely cyanide blue, another name for Prussian blue..."

Remarks

The author observes that 'Prussian blue' was transliterated as 'blu kiyāns' (cyanide blue) or even misinterpreted as 'blue from Iran' because 'Persian' and 'Prussian' are written similarly in the treatise (p. 170). This section highlights the challenges of deciphering transliterated technical terms (p. 160).