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Ancient Concepts, Sciences & Systems
Eternal India
encyclopedia
CHEMICAL PRACTICES AND ALCHEMY
Chemical practices as a purposeful and useful skill have a hoary
antiquity in India. The first indication of chemistry at work in ancient
India is with the baking of clay and production of pottery. Even
though pottery making appears to be an artist’s work in creativity,
in reality it reflects the development of processes which involve
heating, fusion, evaporation and the treatment of minerals. Some of
the chemical practices for which ancient India was famous are :
metal working, mineral processing, composition of mortar and ce-
ment, brewing of fermented drinks, extraction of oils, production
and use of vegetable pigments and dyes and glass blowing.
PREHISTORIC
Pottery making was widely prevalent in India even prior to 1500
B.C. But this pottery was mainly handcrafted and not made by
using the potter’s wheel. There were no kilns to bake the pots, but
the pots were kept in a circular pit and covered partially with
sherds. These were then lighted to raise a small fire. Handcrafted,
improperly baked pots have been found in excavations of prehistoric
rock shelters at Lekhalia in Mirazpur district of Uttar Pradesh,
Nagarjunakonda of Andhra Pradesh etc.
In the Indus Valley Civilization, also called the Harappan cul-
ture which flourished from 2300.-1750 B.C. pottery making had
reached a very sophisticated level. Excavations at Kalibangan, a
site in the Ganganagar district of Rajasthan, have revealed wheel-
made pots in the red and black washings. Kalibangan is regarded
as pre-Harappan culture (2600-2400 B.C.) and the presence of
wheel-made pots is an indication that the potter’s wheel is more
ancient than the Indus Valley Civilization.
The pottery of the Indus Valley Civilization is wheel made,
comprising of the variously coloured (red, buff, grey) alluvial soil of
the Indus river bank. The pots were painted in black colour over a
red surface. Mica, sand and lime were used for tempering the pots.
Pots were baked in kilns using wood or charcoal for firing purposes.
The kilns were round, cylindrical or pear shaped with or without
brick layering.
That the potters of the Indus Valley Civilization were highly
skilled craftsmen can be seen from the intricate decorative designs
carved on the pots. The designs consist of plant or animal forms,
geometrical shapes like squares and triangles and occasionally
human figures also. The technique of glazing the surface of the
pottery was also known to the Indus Valley potter. Glazing mate-
rials such as finely crushed quartz or white sand, glassy-flux and
colouring matter were mixed with gums and other organic sub-
stances to create a shiny polished surface. According to Mackay,
an archaeological expert on Mohenjodaro, the potters of the Indus
Valley Civilization had perfected the art of pottery to a high degree
of perfection.
Terracotta doll making was another craft of the Indus Valley
Civilization which involved production of human figurines that were
entirely fashioned by hand.
Metal craft was not prevalent very much during the pre-Indus
Valley culture, though there are evidences of the use of copper in a
few places like Kalibangan. But the Indus Valley Civilization can
boast of highly skilled metalsmiths who fashioned artefacts out of
copper, bronze, lead, silver, gold and electrum (an alloy of gold and
silver). Gold was used primarily for ornaments. Metal crafting pro-
cedures such as soldering, sheet making, rivetting, coiling and lost-
wax metal casting process
(cire perdue
casting) were known to the
Indus Valley metalsmiths. Copper sheets were fashioned into
vessels, while bronze was used for casting. The bronze statue of
the ‘dancing girl’ discovered at Mohenjodaro was probably a lost
wax cast product, even though excavations have not revealed
mould casts.
Metals, particularly copper and bronze, were widely used to
manufacture hand tools like axes, chisels, drills, reamers, metal
mirrors and weapons like daggers, knives, spears, arrowheads etc.
Even though the metallic instruments had some percentage of tin,
alloying perhaps had not been perfected by the metalsmiths. How-
ever there are indications that metalcraft techniques like cold work-
ing and annealing were known to the metalsmiths. One of the most
surprising aspects in the Indus Valley Civilization however is the
absence of iron objects indicating that iron metallurgy was un-
known.
Other chemical practices of the Indus Valley Civilization include
the use of gypsum and lime as plastering material to cover the walls
made out of burnt brick. Many minerals such as lapis luzuli,
turquoise,alabaster, haematite, agate etc were used for ornamental
purposes.
VEDIC AGE
This is the most distinctive phase in the cultural history of
ancient India which perhaps began at a period not earlier than 1500
B.C and thought to be post-Harappan in time. The people of the
Vedic age generally known as Indo Aryans have left written records
(in the form of
Samhitas, Aranyakas, Upanishads
etc) from where
we can get glimpses of chemical practices of that period.
The
RigVeda,
hailed as the earliest ever human writing, men-
tions
Ayas
meaning metal. Silver and gold plates were used for
sacrificial rites.
Atharva Veda
opines that gold ensures longevity
Painted Grey ware : dish (Ahicchatra) and bowl (Panipat)