Amazing Science, Cosmology and Psychology, Medicine (Ayurveda)
Part 5Minerals and Metals
The Kautiliya Arthasastra Minerals and Metals and Ethnobiological Information in Kautilya's Arthasastra
It is surprising that even in the I Millennium BC, they had developed an elaborate terminology for different metals, minerals and alloys. Brass (arakuta) was known, so also steel (vrattu), bronze (kamsa), bell-metal (tala) was an alloy of copper with arsenic, but tin-copper alloy was known as trapu. A bewildering variety of jewellery was also classified and given distinctive names.
Information and instructions about various other aspects of social life, including man's relationship with animals and plants.
Ethnobiological Information contained in the Arthasastra. It deals with forests, plants, animals, animal husbandry including veterinary suggestions, agriculture medicinal-industrial,commercial importance and application of flora and fauna, and the uses of plants and animals in biological and chemical warfare, besides weapon making and other military uses.
The Kautiliya Arthasastra, a Sanskrit work of the c. 4th century B.C., is more known for its contents on politics and statecraft. But the book contains information and instructions about various other aspects of social life, including man's relationship with animals and plants. The present monograph of Prof. P. Sensarma is an excellent treatise in lucid English on the Ethnobiological Information contained in the Arthasastra. It deals with forests, plants, animals, animal husbandry including veterinary suggestions, agriculture medicinal-industrial, commercial importance and application of flora and fauna, and the uses of plants and animals in biological and chemical warfare, besides weapon making and other military uses
1600 years old Iron Pillar that does not rust as a The Corrosion Resistant Iron Pillar of Delhi
The pillar—over seven meters high and weighing more than six tonnes—was erected by Kumara Gupta of Gupta dynasty that ruled northern India in AD 320-540.
Press Trust of India
The Indian Express 26 January 2004
Experts at the Indian Institute of Technology have resolved the mystery behind the 1,600-year-old iron pillar in Delhi, which has never corroded despite the capital's harsh Metallurgists at Kanpur, IIT have discovered that a thin layer of "misawite", a compound of iron, oxygen and hydrogen, has protected the cast iron pillar from rust.
The protective film took form within three years after the erection of the pillar and has been growing ever so slowly since then. After 1,600 years, the film has grown just one-twentieth of a millimeter thick, according to R. Balasubramaniam of the IIT.
In a report published in the journal Current Science Balasubramanian says, the protective film was formed catalytically by the presence of high amounts of phosphorous in the iron—as much as one per cent against less than 0.05 per cent in today's iron.
The high phosphorous content is a result of the unique iron-making process practiced by ancient Indians, who reduced iron ore into steel in one step by mixing it with charcoal.
Modern blast furnaces, on the other hand, use limestone in place of charcoal yielding molten slag and pig iron that is later converted into steel. In the modern process most phosphorous is carried away by the slag. The pillar—over seven meters high and weighing more than six tonnes—was erected by Kumara Gupta of Gupta dynasty that ruled northern India in AD 320-540.
Stating that the pillar is "a living testimony to the skill of metallurgists of ancient India", Balasubramaniam said the "kinetic scheme" that his group developed for predicting the growth of the protective film may be useful for modeling long-term corrosion behaviour of containers for nuclear storage applications. The Delhi iron pillar is testimony to the high level of skill achieved by ancient Indian iron smiths in the extraction and processing of iron. The iron pillar at Delhi has attracted the attention of archaeologists and corrosion technologists as it has withstood corrosion for the last 1600 years.
Minerals and Metals in Kautilya's Arthasastra
It is interesting to note that Kautilya prescribes that the state should carry out most of the businesses, including mining. No private enterprise for Kautilya! One is amazed at the breadth of Kautilya's knowledge. Though primarily it is a treatise on statecraft, it gives detailed descriptions and instructions on geology, agriculture, animal husbandry, metrology etc. Its encyclopedic in its coverage and indicates that all these sciences were quite developed and systematized in India even 2500 years ago. It is surprising that even in the I Millennium BC, they had developed an elaborate terminology for different metals, minerals and alloys. Brass (arakuta) was known, so also steel (vrattu), bronze (kamsa), bell-metal (tala) was an alloy of copper with arsenic, but tin-copper alloy was known as trapu. A bewildering variety of jewellery was also classified and given distinctive names.
The chapter begins with the importance of 'mines and metals' in the society and here we are told that one of the most crucial statements in the Arthasastra is that gold, silver, diamonds, gems, pearls, corals, conch-shells, metals, salt and ores derived from the earth, rocks and liquids were recognized as materials coming under the purview of mines. The metallic ores had to be sent to the respective Metal Works for producing 'twelve kinds of metals and commodities'. Though the authors wish to show the importance of mines and metals in the society, yet what they point to is their importance for the state and the powers that the state exercised over them. Perhaps, Kautilya himself did not treat the matter so and focused to show its importance for the state alone as the book Arthasastra is on statecraft and not on society.
The next section deals with the gem minerals and is treated more extensively than others. We wonder if it is not due to the fact that the gem minerals reflected the richness of Indian kings. Here we are told that Mani-dhatu or the gem minerals were characterized in the Arthasastra as 'clear, smooth, lustrous, and possessed of sound, cold, hard and of a light color'. Excellent pearl gems had to be big, round, without a flat surface, lustrous, white, heavy, and smooth and perforated at the proper place. There were specific terms for different types of jewellery: Sirsaka (for the head, with one pearl in the centre, the rest small and uniform in size), avaghataka (a big pearl in the center with pearls gradually decreasing in size on both sides), indracchanda (necklace of 1008 pearls), manavaka (20 pearl string), ratnavali (variegated with gold and gems), apavartaka (with gold, gems and pearls at intervals), etc. Diamond (vajra) was discovered in India in the pre-Christian era.
The Arthasastra described certain types of generic names of minerals red saugandhika, green vaidurya, blue indranila and colorless sphatika. Deep red spinel or spinel, ruby identified with saugandhika, actually belongs to a different (spinel) family of minerals. Many other classes of gems could have red color. The bluish green variety of beryl is known as aquamarine or bhadra, and was mentioned in the Arthasastra as uptpalavarnah (like blue lotus). The Arthasastra also mentions several subsidiary types of gems named after their color, luster or place of origin. Vimalaka shining pyrite, white-red jyotirasaka, (could be agate and carnelian), lohitaksa, black in the centre and red at the fringe (magnetite; and hematite on the fringe?), sasyaka blue copper sulphate, ahicchatraka from Ahicchatra, suktichurnaka powdered oyster, ksiravaka, milk coloured gem or lasuna and bukta pulaka (with chatoyancy or change in lustre) which could be cat's eye, a variety of chrysoberyl, and so on.
The authors further mention that at the end was mentioned kacamani, the amorphous gems or artificial gems imitated by coloring glass. The technique of maniraga or imparting colour to produce artificial gems was specifically mentioned.
We are told that the Arthasastra also mentions the uses of several non-gem mineral and materials such as pigments, mordants, abrasives, materials producing alkali, salts, bitumen, charcoal, husk, etc.
Pigments were in use such as anjan ,( antimony sulphide), manahsil ( red arsenic sulphide), haritala, (yellow arsenic sulphide) and hinguluka (mercuric sulphide), Kastsa (green iron sulphate) and sasyaka, blue copper sulphate. These minerals were used as coloring agents and later as mordants in dyeing clothes. Of great commercial importance were metallic ores from which useful metals were extracted. The Arthasastra did not provide the names of the constituent minerals beyond referring to them as dhatu of iron (Tiksnadhatu), copper, lead, etc.
Having reviewed the literary evidence the authors maintain that the Arthasastra is the earliest Indian text dealing with the mineralogical characteristics of metallic ores and other mineral-aggregate rocks. It recognizes ores in the earth, in rocks, or in liquid form, with excessive color, heaviness and often-strong smell and taste. A gold-bearing ore is also described. Similarly, the silver ore described in the Arthasastra seems to be a complex sulphide ore containing silver (colour of a conch-shell), camphor, vimalaka (pyrite?).
The Arthasastra describes the sources and the qualities of good grade gold and silver ores. Copper ores were stated to be 'heavy, greasy, tawny (chalcopyrite left exposed to air tarnishes), green (color of malachite), dark blue with yellowish tint (azurite), pale red or red (native copper). Lead ores were stated to be grayish black, like kakamecaka (this is the color of galena), yellow like pigeon bile, marked with white lines (quartz or calcite gangue minerals) and smelling like raw flesh (odour of sulphur). Iron ore was known to be a greasy stone of pale red colour, or of the colour of the sinduvara flower (hematite). After describing the above metallic ores or dhatus of specific metals, the Arthasastra writes: In that case vaikrntaka metal must be iron itself, which used to be produced by the South Indians starting from the magnetite ore. It is not certain whether vaikrntaka metal was nickel or magnetite based iron. Was it the beginning of the famous Wootz steel?
The Arthasastra mentions specific uses of various metals of which gold and silver receive maximum attention. The duties of suvarna-adhyaksah, the 'Superintendent of Gold, are defined. He was supposed to establish industrial outfits and employ sauvarnikas or goldsmiths, well versed in the knowledge of not only gold and silver, but also of the alloying elements such as copper and iron and of gems which had to be set in the gold and silver wares. Gold smelting was known as suvarnapaka. Various ornamental alloys could be prepared by mixing variable proportions of iron and copper with gold, silver and sveta tara or white silver which contained gold, silver and some coloring matter. Two parts of silver and one part of copper constituted triputaka. An alloy of equal parts of silver and iron was known as vellaka.
Gold plating (tvastrkarma) could be done on silver or copper. Lead, copper or silver objects were coated with a gold-leaf (acitakapatra) on one side or with a twin-leaf fixed with lac etc. Gold, silver or gems were embedded (pinka) in solid or hollow articles by pasting a thick pulp of gold, silver or gem particles and the cementing agents such as lac, vermilion, red lead on the object and then heating.
The Arthasastra also describes a system of coinage based on silver and copper. The masaka, half masaka, quarter masaka known as the kakani, and half kakani, copper coins (progressively lower weights) had the same composition, viz., one-quarter hardening alloy and the rest copper.
The Arthasastra specifies that the Director of Metals (lohadhyakasa) should establish factories for metals (other than gold and silver) viz., copper, lead, tin, vaikrntaka, arakuta or brass, vratta (steel), kamsa (bronze), tala (bell-metal) and loha (iron or simply metal), and the corresponding metal-wares. In the Vedic era, copper was known as lohayasa or red metal. Copper used to be alloyed with arsenic to produce tala or bell metal and with trapu or tin to produce bronze. Zinc in India must have started around 400 BC in Taxila. Zawar mines in Rajasthan also give similar evidence. Vaikrntaka has been referred to some times with vrata, which is identified by many scholars including Kangle, as steel. On the top of it, tiksna mentioned as iron, had its ore or dhatu, and the metal was used as an alloying component. Iron prepared from South Indian magnetite or vaikrantakadhatu was wrongly believed to be a different metal.
The authors further mention that at the end was mentioned kacamani, the amorphous gems or artificial gems imitated by coloring glass. The technique of maniraga or imparting colour to produce artificial gems was specifically mentioned.
We are told that the Arthasastra also mentions the uses of several non-gem mineral and materials such as pigments, mordants, abrasives, materials producing alkali, salts, bitumen, charcoal, husk, etc.
Pigments were in use such as anjan ,( antimony sulphide), manahsil ( red arsenic sulphide), haritala, (yellow arsenic sulphide) and hinguluka (mercuric sulphide), Kastsa (green iron sulphate) and sasyaka, blue copper sulphate. These minerals were used as coloring agents and later as mordants in dyeing clothes. Of great commercial importance were metallic ores from which useful metals were extracted. The Arthasastra did not provide the names of the constituent minerals beyond referring to them as dhatu of iron (Tiksnadhatu), copper, lead, etc.
Having reviewed the literary evidence the authors maintain that the Arthasastra is the earliest Indian text dealing with the mineralogical characteristics of metallic ores and other mineral-aggregate rocks. It recognizes ores in the earth, in rocks, or in liquid form, with excessive color, heaviness and often-strong smell and taste. A gold-bearing ore is also described. Similarly, the silver ore described in the Arthasastra seems to be a complex sulphide ore containing silver (colour of a conch-shell), camphor, vimalaka (pyrite?).
The Arthasastra describes the sources and the qualities of good grade gold and silver ores. Copper ores were stated to be 'heavy, greasy, tawny (chalcopyrite left exposed to air tarnishes), green (color of malachite), dark blue with yellowish tint (azurite), pale red or red (native copper). Lead ores were stated to be grayish black, like kakamecaka (this is the color of galena), yellow like pigeon bile, marked with white lines (quartz or calcite gangue minerals) and smelling like raw flesh (odour of sulphur). Iron ore was known to be a greasy stone of pale red colour, or of the colour of the sinduvara flower (hematite). After describing the above metallic ores or dhatus of specific metals, the Arthasastra writes: In that case vaikrntaka metal must be iron itself, which used to be produced by the South Indians starting from the magnetite ore. It is not certain whether vaikrntaka metal was nickel or magnetite based iron. Was it the beginning of the famous Wootz steel?
The Arthasastra mentions specific uses of various metals of which gold and silver receive maximum attention. The duties of suvarna-adhyaksah, the 'Superintendent of Gold, are defined. He was supposed to establish industrial outfits and employ sauvarnikas or goldsmiths, well versed in the knowledge of not only gold and silver, but also of the alloying elements such as copper and iron and of gems which had to be set in the gold and silver wares. Gold smelting was known as suvarnapaka. Various ornamental alloys could be prepared by mixing variable proportions of iron and copper with gold, silver and sveta tara or white silver which contained gold, silver and some coloring matter. Two parts of silver and one part of copper constituted triputaka. An alloy of equal parts of silver and iron was known as vellaka.
Gold plating (tvastrkarma) could be done on silver or copper. Lead, copper or silver objects were coated with a gold-leaf (acitakapatra) on one side or with a twin-leaf fixed with lac etc. Gold, silver or gems were embedded (pinka) in solid or hollow articles by pasting a thick pulp of gold, silver or gem particles and the cementing agents such as lac, vermilion, red lead on the object and then heating.
The Arthasastra also describes a system of coinage based on silver and copper. The masaka, half masaka, quarter masaka known as the kakani, and half kakani, copper coins (progressively lower weights) had the same composition, viz., one-quarter hardening alloy and the rest copper.
The Arthasastra specifies that the Director of Metals (lohadhyakasa) should establish factories for metals (other than gold and silver) viz., copper, lead, tin, vaikrntaka, arakuta or brass, vratta (steel), kamsa (bronze), tala (bell-metal) and loha (iron or simply metal), and the corresponding metal-wares. In the Vedic era, copper was known as lohayasa or red metal. Copper used to be alloyed with arsenic to produce tala or bell metal and with trapu or tin to produce bronze. Zinc in India must have started around 400 BC in Taxila. Zawar mines in Rajasthan also give similar evidence. Vaikrntaka has been referred to some times with vrata, which is identified by many scholars including Kangle, as steel. On the top of it, tiksna mentioned as iron, had its ore or dhatu, and the metal was used as an alloying component. Iron prepared from South Indian magnetite or vaikrantakadhatu was wrongly believed to be a different metal.
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