Susruta Samhita
The portion in Susruta Samhita, which explains the preparation and
use of alkalies, occupies a prominent place in Indian medical chemistry. It is
said that alkalies were used to clean surgical instruments, which were used to
cut the diseased parts of human body. (the term СksaraТ itself means Сthat which removes away the affected parts of the bodyТ). Plates of iron, silver and gold were dipped in alkaline liquids
before mixing with medicines.
Susruta classifies alkalies into mrdu, tiksna and
madhyama. He gives the preparation of each category. Some of them are
used for external application and some for internal administration. They
are used externally for skin diseases like kusta, tumors, piles etc. and
internally for abdominal tumors, indigestion, urinary deposits, intestinal
worms etc. devices to store them are also advised. According to him, the
sharp, saline taste of alkali when mixed with acid becomes very mild and gives
up its sharpness. That is why acid neutralises alkaly.
Different metals like bronze, iron, gold, silver, lead, copper,
tin and different salts like rock salt, sea salt etc are enumerated in the
Samhita. Roasting of iron and other metals so as to render them fit for
internal administration has been described. The thin leaves of metals
were plastered with a paste of the salts and afterwards subjected to roasting
and were converted into their respective oxides, chlorides or oxichlorides.
This can be considered a crude process for the preparation of the metallic
salts.
Brhatsamhita (6th Century AD)
Varahamihira, in his Brhatsamhita, refers to mordants like alum
and sulphate or iron for the fixing of dyes on textile fabrics. It also alludes
to cosmetics, scented hair dyes, perfumes etc. It also contains
information on various cement preparations, which may be classified under two
heads: rock cement (vajralepa) and metal cement (vajra samghata). These
varieties of cement were applied to the walls and roofs of temples and other
buildings.
Alchemy in Tantric Period (800 AD to 1600 AD)
The flourishing of chemistry in India, especially alchemy, has an
interesting phase during the period of tantra. The tantric cult in India
was an admixture of alchemical processes on the one hand and grotesque rites on
the other, centred on the worship of Siva and Parvati. We also have a class of
tantras, which is an admixture of Buddhist and Saiva cults. Rasaratnakara
ascribed to Nagarjuna belongs ato this category. According to tantric
cult, a man should preserve his body by means of mercury and
medicaments. According to tantrics, mercury was produced by the creative
conjunction of Siva and Parvati and mica was produced from Parvati. The
combination of mercury and mica was believed to be destructive of death and
poverty.
Sarvadarsana Samgraha of Madhavacarya which elaborates the sixteen
philosophical systems current in 14th Cent AD, includes raseswara
darsana or mercurial system as one among them. According to this
darsana, different preparations of mercury can enable a man to be free from old
age and death, ie to obtain jivan mukti. Rasa is called parada because,
it enables one to overcome the worldly affairs.
Rasarnava (asked in UPSC GS MAINS 2012) of unknown authorship, Rasaratnakara of Nagarjuna and
Rasaratna samuchaya of Vagbhata are some of the important works of Indian
alchemy written during the tantric period. Rasaratnakara and Rasarnava are
tantras pure in which alchemy is incidentally dealt with. Rasaratnasamuchaya
is a systematic treatise on pharmacy and medicine. Rasaratnakara of
Nagarjuna contains descriptions of alchemical processes and preparations of
mercurial compounds. Extraction of zinc, mercury and copper are described
by him. He also elaborates on the preparation of crystalline red sulphide
of mercury (swarnasindura or makaradhwaja) which is used as medicine for many
ailments.
There are also works written in regional languages like Tamil,
Telugu, Kannada, Malayalam, Bengali, Marathi, Oriya and Gujarati on
alchemy. Here, Tamil works on siddha vaidya, about two hundred in number,
deserves mention. Works of Agastya, Nandiswara, Romarshi and Kailasamuni
are important among them. A comparative study of the alchemical ideas of these
Tamil and Sanskrit works has not yet been initiated.
According to tantric cult, siddhis are of two types - dehasiddhi
(development of the body) and loha siddhi (development of metals).
- The first pertains to making mercury capable of changing the molecules of lower metals into molecules of higher metals. Mercury, which is capable of this, can certainly transform human molecules also. This is dehasiddhi.
- Lohasiddhi is called alchemy or dhatuvada. Dehasiddhi is obtained through lohasiddhi. Gradually, devices to refine metals led to the making of their powders, which were used as medicines.
As part of these alchemical processes, there are certain methods
to purify mercury. Indian alchemists had adopted 18 methods for this
purpose. They also make classification of chemical
substances into maharasa, uparasa, datu, ratna and visa. Certain refining
processes of metals and mine products, mixtures of mercury also deserve special
mention.
An important feature of Indian alchemy is the description of
certain plants used in alchemical processes. About two hundred plants are
referred to in this connection. We get an elaborate description of the
laboratories and the instruments from these alchemical works.