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165
medical works, composed probably in the sixteenth
and the seventeenth centuries e.g. Rasakaumudi by
M膩dhava, Rasaratnapradipa and Bhaishajyaratn膩vali
by Govindad膩sa etc.
30 Let us see what Needham' comments about the
knowledge of the Indians, of mineral acids, after describing
the above episode of the seventh century scholar in the
Chinese court.
One of the best things about this account is
its date, which is very firm. Foreshadowing
perhaps the later "alkahest" or universal sovlent
of Paracelsian iatro-chemistry this passage
suggests at any rate that a mineral acid was
known in the seventh century AD. It gives some
colour to the hints about strong acids in Ray's
history of chemistry in India. Already in the
11th century AD the Ras膩r峁嘺vakalpa has much on
the "fixation" or "killing" of metals. The
Ras膩r峁嘺va Tantra (dated by Ranou and Filliozat
as of the 12th century AD) speaks of the "killing
of iron and other metals by a vida (solvent?)
which is prepared from green vitriol (k膩sisa),
pyrites etc. From the Rasaratnasamu莽莽aya
(compiled according to Renou and Filliozat
about 1300 AD) which reproduces material from
the "Rasendra-ch奴d膩ma峁噄" of somadeva (12th or
13th century AD) the process of "killing"
certainly seems to be the formation of salts
from metals. Neogi drew attention long ago to
the apparent presence of oil of vitriol in the
later Indian alchemical treatises under the name
"essence of alum", produced by distillation.
This is certainly mentioned in the
"Rasaratnasamuccaya" and in the Rasaprakashsudhakara
of Yasodhara (13th century AD), though they do not
distinctly say that the alum and the ferrous
30.
Needham, Joseph (1), Vol. 5, Pt. IV, p. 198.