History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c20.s2.t4.3

v1.c20.s2.t4.3

In the texts dealing with alchemy and allied topics of ancient and middle ages we come across words like *loharañjaka*, *rasarañjaka*, *sūtarañjaka* etc¹². It is quite probable that in 4th or 5th century A.D., people were efficient in the techniques of colouring metals and minerals for several purposes. *Rasārṇava*, a tantric work says, "Iron, lead and copper are coloured by means of calamine - the whole thing turns into gold"¹³. *Rasaka* (calamine) is of three kinds, of the colour of the earth, of the colour of stones and of the appearance of treacle. *Rasaka* mixed with certain organic matters and roasted three times with copper converts the copper into a golden stuff. To obtain vermilion (*sindura*) of the colour of rising sun, it is advised that ash of mercury and sulphur of equal weights should be rubbed and roasted in a covered crucible. Blue vitriol (*tuttham*) which is of the colour of the neck of peacock, saffron (*kunkumam*), calamine (*rasaka*) and also the excreta of a young calf, the poisons (*visa halahala*), powdered *Plumbago zeylanica*, (*raktacitracūrṇa*), all in equal proportions should be rubbed with acids and dried in shade.