Dear Dominic,

A little passage like this is a treasure. Is there any possibility that mṛtsnā
refers to an agent that may have been used to treat the leaves so as to
keep them supple and/or free of insects, etc.? Or might it have
been used in smoothing the leaves? A useful summary of palm-leaf writing technology -
http://www.idc.iitb.ac.in/resources/dt-july-2009/Palm.pdf
refers to several such agents, though none are earths (as one would expect
mṛtsnā to have been). (The illuminated folio labeled in the article as fig. 1.2 must be
much earlier than the 18th c. date assigned to it here, by the way.)

best,
Matthew