On these palm leaves the custom is to write with an iron stile held nearly upright, and steadied by a nick cut to receive it in the thumb nail of the left hand.
The furrow made by the pressure of the steel is rendered visible by the application of charcoal ground with a fragrant oil, to the odour of which the natives ascribe the remarkable state of preservation in which their most scared books are found, its aromatic properties securing the leavesfrom destruction by white ants and other insects”
For this purpose a resin is used, called dumula by the natives, who dig it up from beneath the surface of the lands from beneath the surface of which the forest has disappeared)…
– (Ceylon / by Sir James Emerson Tennent – Volume 1 – page 513 – London 1859 A.D)
( Sri Lanka was called Ceylon before 1972 )