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→Chemistry in Ancient India
Rigveda mentions the Asvini devatas, the divine physicians, who when invoked gave sight to the blind and made the lame walk, restoring people to good health. The Vedas mention many plants, herbs, minerals and metals as the sources of healing powers, used for treating ailments though their potencies are not described. A Rigveda sukta (1.162) gives an account of the bronze cauldron. Gold was used for ornaments like anklets, rings, etc. Mention of metal vessels, tools and armour, seals made mainly of copper, bronze, affords evidence of the knowledge of metal working.<ref name=":1" /> According to Rigveda, tanning of leather and dyeing of cotton was practiced during this period. References are found in the Rigveda about the preparation of tanning of leather and hides for use as slings, bead strings, reins and whips.<ref name=":1" />
Rigveda mentions the Asvini devatas, the divine physicians, who when invoked gave sight to the blind and made the lame walk, restoring people to good health. The Vedas mention many plants, herbs, minerals and metals as the sources of healing powers, used for treating ailments though their potencies are not described. A Rigveda sukta (1.162) gives an account of the bronze cauldron. Gold was used for ornaments like anklets, rings, etc. Mention of metal vessels, tools and armour, seals made mainly of copper, bronze, affords evidence of the knowledge of metal working.<ref name=":1" /> According to Rigveda, tanning of leather and dyeing of cotton was practiced during this period. References are found in the Rigveda about the preparation of tanning of leather and hides for use as slings, bead strings, reins and whips.<ref name=":1" />
There are ample references of a number of fermented drinks. Soma, the rasa (juice) is a fermented juice from the stems of soma plant regarded as the Amrita, is said to heal all ailments and bestow immortality. Among fermented liquors, there is a mention of madhu,a drink supplied at feasts, and sura, another drink probably a kind of beer brewed from barley grain. Curds or fermented milk constituted an important item of diet. Clothes were mainly made of wool and the garments were often dyed red, purple and brown; people demonstrated their acquaintance with the art of dyeing with natural vegetable coloring material.<ref name=":1" />
There are ample references of a number of fermented drinks. Soma, the rasa (juice) is a fermented juice from the stems of soma plant regarded as the Amrita, is said to heal all ailments and bestow immortality. Among fermented liquors, there is a mention of madhu, a drink supplied at feasts, and sura, another drink probably a kind of beer brewed from barley grain. Curds or fermented milk constituted an important item of diet. Clothes were mainly made of wool and the garments were often dyed red, purple and brown; people demonstrated their acquaintance with the art of dyeing with natural vegetable coloring material.<ref name=":1" />
Yajurveda clearly mentions six metals<ref name=":1" /> - Ayas (gold), Hiranya (silver), Loha (copper), Shyama (iron), Sisa (lead), Trapu (tin). Atharvaveda names Harita (yellow) as gold, Rajata (white) as silver and Lohita (red) as copper.
Yajurveda clearly mentions six metals<ref name=":1" /> - Ayas (gold), Hiranya (silver), Loha (copper), Shyama (iron), Sisa (lead), Trapu (tin). Atharvaveda names Harita (yellow) as gold, Rajata (white) as silver and Lohita (red) as copper.
Some important concepts of chemistry that are studied in modern times were proposed in ancient times primarily in Samkhya and Vaiseshika darshanas.
Some important concepts of chemistry that are studied in modern times were proposed in ancient times primarily in Samkhya and Vaiseshika darshanas.
According to the Samkhya school's theory of matter, '''tanmatras''' are five subtle elements or infra-atomic particles imperceptible to the human senses as a result of continued differentiation and unequal aggregation of gunas from Prakriti as explained above during evolution. These subsequently gave rise, by the same process, to five grosser elements - the Panchamahabhutas namely, akasa (space or ether), vayu (air), tejas (fire), apa (water), and bhumi (earth). They are regarded as representing five abstract principles, or rather a classification of substances on the basis of their properties and states of aggregation. Earth, water and air may be viewed as comprising all the so-called elements or compounds of chemistry.
The Samkhya theory posits that the world is a product of ordered evolution from an original undifferentiated Prakriti, and one becoming many. The Vaiseshika darshana propounds that the world arises out of atoms combining together in various ways, i.e., many becoming one.
According to the Samkhya school's theory of matter,<ref name=":1" /> '''tanmatras''' are five subtle elements or infra-atomic particles imperceptible to the human senses as a result of continued differentiation and unequal aggregation of gunas from Prakriti as explained above during evolution. These subsequently gave rise, by the same process, to five grosser elements - the Panchamahabhutas namely, akasa (space or ether), vayu (air), tejas (fire), apa (water), and bhumi (earth). They are regarded as representing five abstract principles, or rather a classification of substances on the basis of their properties and states of aggregation. Earth, water and air may be viewed as comprising all the so-called elements or compounds of chemistry.
* Bhumi or kshiti typifies all solids
* Bhumi or kshiti typifies all solids
* Vayu typifies all gases
* Vayu typifies all gases
According to Samkhya, atoms (Anu-s) of these grosses elements are composite units made up of infra-atomic particles, the tanmatras. The chemical theory of the Nyaya-Vaiseshika system involves the theory of Anu-s or atoms comparable to the tanmatras of the Samkhya philosophy.
According to Samkhya, atoms (Anu-s) of these grosses elements are composite units made up of infra-atomic particles, the tanmatras. The chemical theory of the Nyaya-Vaiseshika system involves the theory of Anu-s or atoms comparable to the tanmatras of the Samkhya philosophy. The Samkhya virtually substantizes the “gunas”; the Vaiseshikas take them to be qualities which are always found in some dravya. According to Maharshi Kanada, every material of this universe is made up of kana or parmanu (atom) which are invisible, indivisible, eternal and indestructible. There are two states of anu- a state of motion and a state of absolute rest.
The Vaiseshika sutras<ref name=":3">Gupta, B. (2012). ''An introduction to Indian philosophy: Perspectives on Reality, Knowledge, and Freedom''. Routledge.</ref>, define and explain the nature of dravya or substance, and classifies all dravyas or things of the world into nine: Earth, water, fire, air, ether/space, time, space, soul and manas (mind).
Each of the first five substances possess a unique quality, which makes the substance what it is. Maharshi Kanada recognized four kinds of atoms each having a unique quality or guna
# kshiti or earth - smell
# apa or water - taste
# tejas or fire - color
# vayu or air - touch
The first four are knowable by outer perception. The substances of earth, water, fire, and air are eternal and non-eternal. The atoms of these four substances are partless and eternal, because as partless they can neither be produced nor destroyed. The fifth substance, akasha or ether, has the characteristic of sound and is indivisible, eternal, and non-perceptible.<ref name=":3" /> Akasa (ether), according to Kanada, has no atomic structure; it is inert and ubiquitous serving only as the substratum of sound which is supposed to travel in the form of waves in the manifesting medium of vayu (air). Atoms are the primordial infinitesimal particles of everything except space or Akasha. Each atom has its individual characteristics, and it combines with other atoms to form the larger entities similar to molecules. These atoms are characterized by their characteristic mass, basic molecular structure such as dyad, triad, etc, fluidity (or it’s opposite), viscosity (or its opposite), velocity (or quantity of impressed motion- Vega) and other characteristic potential color, taste, smell or touch not produced by chemical operation. It is these four kinds of atoms involved in all chemical reactions while the space remains unaffected.<ref name=":3" />
That matter is ultimately made of indivisible building blocks, thus appeared in India as part of philosophical school of thought long before Western inventions.
== Chemistry in Ancient India ==
== Chemistry in Ancient India ==
In ancient India, chemistry served medicine on one hand - in the preparation of a number of medicines—and technology on the other—for preparing colors, steels, cements, spirits, etc. While knowledge of metals and oxides was prevalent, of the metallic medicines, mercury was particularly popular. In Rigveda there is a mention of gold, silver, copper, bronze among metals or metallic objects.<ref name=":1" /> The Ramayana and the Mahabharata mention weapons with arrowheads coated with a variety of chemicals, indicating their knowledge of Alchemy. Various chemical processes generally described in the ancient treatises are those of extraction, purification, tempering, calcination, powdering, liquefying, precipitation, washing, drying, steaming, melting, filing, etc. Later, all these processes were applied to various metals, using special apparatuses or yantras and reagents and heating to different degrees—high, average and low.<ref>Chattopadhyaya, D. (1982). ''Studies in the history of science in India'' (Vol. 1). Editorial Enterprises.</ref> Chemistry was vigorously pursued in India during the Mahayana phase of activity of Buddhism as seen from the text Rasaratnakara ascribed to Acharya Nagarjuna.
In ancient India, chemistry served medicine on one hand - in the preparation of a number of medicines—and technology on the other—for preparing colors, steels, cements, spirits, etc. While knowledge of metals and oxides was prevalent, of the metallic medicines, mercury was particularly popular. In Rigveda there is a mention of gold, silver, copper, bronze among metals or metallic objects.<ref name=":1" /> The Ramayana and the Mahabharata mention weapons with arrowheads coated with a variety of chemicals, indicating their knowledge of Alchemy. Various chemical processes generally described in the ancient treatises are those of extraction, purification, tempering, calcination, powdering, liquefying, precipitation, washing, drying, steaming, melting, filing, etc. Later, all these processes were applied to various metals, using special apparatuses or yantras and reagents and heating to different degrees—high, average and low.<ref>Chattopadhyaya, D. (1982). ''Studies in the history of science in India'' (Vol. 1). Editorial Enterprises.</ref> Chemistry was vigorously pursued in India during the Mahayana phase of activity of Buddhism as seen from the text Rasaratnakara ascribed to Acharya Nagarjuna.
=== Chemical Processes ===
Maharshi Kanada further logically explained that density of atom in water is more than air. He also gave the theory of chemical changes and claimed that chemical changes occur because of the various factors and especially due to variations in temperature.
==== Combination of Atoms ====
Atoms may conjoin or disjoin in reactions.<ref name=":3" /> The atoms combine driven by an inherent tendency which is their natural property to form dyads according to Prashastapada and three dyads combine to form a triad, whereas Maharshi Kanada maintained that different atoms combine in different patterns, some in pairs, some in triads, tetrads etc.
Therefore, Prashastapada's Basic unit of n dyads ≡ 1 dyad + 1 dyad… n dyads where n ≥ 1
While Kanada's Atoms combine ≡ basic unit /molecule with two, three or n number of units
==== Effect of Heat ====
A substance may change qualitatively under the influence of heat in its course of existence. The Vaisheshika’s stand on such a change is that with application of heat a substance decomposes into paramanus or the basic unit with zero mass (not the unit of dyad, triad etc) followed by recombination of paramanus with a new basic unit arrangement and order resulting in a new substance. The Vaisheshikas hold that under the influence of heat, substances are broken down to the most basic entity (paramanu) before being transformed in to a new substance whereas the Nyaya school does not believe in decomposition in to the very basic entity.<ref name=":3" />
A nature (Tattva) of the particular substance when it turns into another nature is called transmutation (Utparivartana) in scientific terms. A study on the Changes (Parivartana) and analysis (Visleṣaṇa) of the substance because of its origin and qualities is called Chemical Science of the particular substance. The Change is of two kinds such as
1) Physical Change (Bhautika Parivartana)
2) Chemical Change (Rāsāyanika Parivartana)
The first type of change i.e. the Physical Change, is when the nature of the substance undergoes changes due to various reasons for a particular period of time and returns back to its previous state. For example, a piece of Iron forms into magnet after a deep friction (Gharṣaṇa) on the magnet and returns into being a piece of iron after it loses the magnetic effect. In same manner, water turns into ice at the state of high cooling (Himānka) and returns to liquid state after melting. In second type of change i.e. Chemical Change once the nature of the substance changes it cannot be reversed. For example, Milk turns into curd, and iron turns into rust etc.<ref>Jena, D. (2021). Concept of chemical science in Vedic literature. ''International Journal of Trend in Scientific Research and Development'', ''5''(4), 43. <nowiki>https://www.ijtsrd.com/papers/ijtsrd41144.pdf</nowiki></ref>
=== Yantras ===
Many Rasashastra texts carefully spell out the layout of the laboratory, with four doors, an esoteric symbol (RASALINGA) in the east, furnaces in the southeast, instruments in the northwest, etc.
Many Rasashastra texts carefully spell out the layout of the laboratory, with four doors, an esoteric symbol (RASALINGA) in the east, furnaces in the southeast, instruments in the northwest, etc.