Iron in Ancient India c7.s5.t1.1

c7.s5.t1.1

Besides the question of the composition of Indian iron the author has a suspicion in his mind that the pillars and beams were originally *painted*. Direct evidence on this point is also forthcoming, as Abul Fazal in the 16th century saw the beams at Puri painted.² The peculiar colour of the iron, specially at the top portion of the Delhi pillar, which misled early observers into thinking that the pillar was made of copper or bronze, might have been due to some kind of paint used for painting the pillar. The author has found out two formulæ of such paints used for hardening as well as preserving iron instruments in *Sārangadhar Padhati*, a compendium on miscellaneous subjects of the 14th century by the alchemist Sārangdhar. The first formula is briefly the following: "Grind together *pippali* (piper longum), rock salt and *kushta* wood (costus speciosus or saussurea Lappa) in cow's urine and cover the iron instrument with the mixture thus obtained. On now heating the instrument in the fire and then quenching in oil the instrument will be of superior quality."³ The second formula runs thus: "Grind together the five kinds of salt, mustard and honey and after painting the instrument with the mixture heat in the fire until at "yellow heat" its colour becomes blue like that of the throat of a peacock. The instrument would, on quenching in cold water, be quite good."⁴ Such an instrument will become extremely hard, so much so that "it will penetrate through the hardest armour as if through leaves of trees."¹ These two formulæ bring out two facts of importance. In the first place it is known as an undoubted fact that in the 14th century at any rate the Hindus were quite familiar with the process of hardening iron by quenching hot iron either in oil or water, and in the second place iron, at least iron instruments, were painted with a mixture containing salt and other ingredients and then heated in the furnace. The exact chemical action that takes place is difficult to understand. At first chlorides of iron are produced which perhaps on heating decompose, leaving a coating of the oxides of iron. It is possible that the Delhi and other pillars and beams were painted with a similar mixture and then heated in the fire, the process being continued, possibly with alterations, from early times down to the fourteenth century.