copper sulphate

Ingredients

copper sulphate, gum Arabic, gallic acid, saffron

Preparation Steps

Original Recipe Text

Green inks prepared according to the recipes of Nefeszade (1938). Sample 14 and 15 both contained copper sulphate (indicated by bands at 1107 and 1155 cm-1) and gum Arabic (band at 1205 cm-1) (p. 93). Sample 15 likely contained saffron (p. 94).

Evidence

"The sulphate bands at 1107 cm-1 and 1155 cm-1 were observed which may originate from copper sulphate."

Remarks

Sample 15 was found to be more stable than Sample 14 (p. 93). The difference is attributed to the buffering effect of saffron in Sample 15, which provided a less acidic medium and reduced the degradation reactions caused by copper ions (p. 94). The absence of gallic acid was noted in the discussion of Sample 15's spectrum intensities (p. 93).