Indus valley civilization

We were so advanced.............

Indus Valley Civilization (2600-1900 BC):

The Indus valley civilization was the earliest society, which had developed an elaborate urban system depicted in terms of streets, public baths, temples and granaries etc. They also had the means of mass production of pottery, houses of backed bricks and a script of their own. So we can say that the story of early chemistry in India begins from here.

Pottery: It could be regarded as the earliest chemical process in which materials were mixed, moulded and fired to achieve desirable qualities. Thousands of pieces of pottery were found in the Rajasthan desert, varied in shape, size and colour. They show that prehistoric people knew the art of making pottery by using burnt clay. Coloured and wheel made pottery was found at Harappa. Pottery was decorated with various designs including geometric and floral patterns as well as human and animals figures. Remains of glazed pottery were also found at Mohenjodaro.

Bricks: Burnt bricks were manufactured on a large scale for making houses, drains, boundary walls, public bath etc.

Cement: Gypsum cement had been used in the construction of a well in Mohenjodaro. It was light grey and contained sand, clay, traces of calcium carbonate and lime.

Minerals: The Indus valley people used a number of minerals for a variety of useful products such as medicinal preparations, plasters, hair washes etc. Faience, which is a sort of proto-glass, was quite popular with the Harappans and was used for ornaments. They also smelted and forged a variety of objects from lead, silver, gold, and copper; and also used tin and arsenic to improve the hardness of copper for making artefacts.

Chemical Arts and Crafts in Later Periods

Glass making, pottery, jewellery making, dyeing of clothes and tanning of leather etc. were the major chemical arts and crafts in the early periods. As a result of this expanded activity, the alchemical knowledge increased. Following were the major chemical products that contributed to the development of chemistry.

Glass: Glass is a fused solid mixture of a number of substances like lime, sand, alkali and metallic oxides. It is of various kinds - transparent, opaque, coloured and colourless. No glass objects were found at the sites of the Indus valley civilization, except for some glazed and faience articles. A number of such glass objects were found at Maski in south India (1000-900BC) , Hastinapur and Taxila (1000-200BC). In this period glass and glazes were coloured by the addition of colouring agents like metal oxides. Ramayana, Brhatsamhita, Kautilya's Arthasatra and Sukranitisara mention the use of glass. There is ample evidence to suggest that ancient India glass making was quite widespread and a high degree of perfection was achieved in this craft. There was a traditional glass factory at Kopia in Basti district of Uttar Pradesh. Glass slag was found at Kolhapur, Nevasa, Paunar and Maheshwar. Glass furnaces of late medieval period were found at Mysore. The Mughal period (AD1526-1707) saw the flourishing of the art of glass making in India.

Paper: From the Chinese traveller I-tsing's account it appears that paper was known to India in the seventh century AD. In the beginning the process of papermaking was simple and more or less similar in all parts of the country. The main centers of paper making in medieval India were Sialkot, Zafarbad, Murshidabad, Ahmedabad, Mysore etc.

Soap: For washing clothes ancient Indians used certain plants and their fruits like the soap nuts of Ritha and Sikakai. Fruits like Sriphala and Sarsapa (Brassica compestris) were also used to wash different kinds of clothes. Guru Nanak's prayer written in the late sixteenth century AD contains the earliest reference to soap. There were references to soap like substances called Phenaka in the second and third century AD texts like Manusmrti and Yajnavalkyasmrti. Indians definitely began to make proper soaps in the eighteenth century AD. In Gujarat, the oil of Eranda (Ricinus communis), seeds of plant Mahua (Madhuca indica) and impure calcium carbonate were used by them. These were used for washing but gradually soft soaps for bathing were made.

Dyeing: Plants and their products like madder, turmeric and safflower were the principal dyeing materials. Orpiment and some insects like lac, cochineal and kermes were the other materials used for dyeing. A number of classical texts like Atharvaveda (1000 BC) mentioned some dye stuffs. Dyes were extracted from inorganic substances by repeatedly soaking and mixing them in water and allowing the materials to settle. Then the solution was taken out and spread on a pot and evaporated to get the dry dye. Some other substances having tinting properties were Kampillaka (Mallotus phillippinesis), Pattanga (Cesalpinia sappan) and Jatuka (a species of Oldenlandia). A large number of other materials were also used for dyeing. Synthetic dyes were made by mid-nineteenth century.

Cosmetics and Perfumes: A large number of references to cosmetics and perfumes in Sanskrit literature were found like in Brhatsamhita of Varahamihira. Cosmetics and perfumes making were mainly practised for the purpose of worship, sale and sensual enjoyment. The Bower Manuscript (Navanitaka) contained recipes of hair dyes which consisted of a number of plants like indigo and minerals like iron powder, black iron or steel and acidic extracts of sour rice gruel. Gandhayukti gave recipes for making scents. It gives a list of eight aromatic ingredients used for making scents. They were: Rodhara, Usira, Bignonia, Aguru, Musta, Vana , Priyangu, and Pathya. The Gandhayukti also gave recipes for mouth perfumes, bath powders, incense and talcum powder. The manufacture of rose water began perhaps in the nineteenth century AD.

Ink: An inkpot was unearthed during the excavations at Taxila, which suggests that ink was known and used in India from fourth century BC. The Ajanta caves displayed some inscriptions that were written with coloured ink, made from chalk, red lead and minium. Chinese, Japanese and Indians had used Indian ink for quite a long time. The recipe for ink was also given in Rasaratnakara of Nityanatha. The ink made from nuts and myrobalans kept in water in an iron pot was black and durable. This ink was used in Malabara and other parts of the country as well. Special ink prepared from roasted rice, lampblack, sugar and the juice of plant Kesurte (Verbsina scandens) was used in the Jain manuscripts. Ink was made both in liquid and solid forms, by using lampblack, gum of the plant Mimosa indica and water in the nineteenth century. Tannin's solution became dark blue-black or greenish by the addition of ferric salts and it seems that this fact was known to Indians during late medieval period, and they used this solution for ink making.

Alcoholic liquors: Somarasa, which was mentioned in the Vedas, was probably the earliest evidence of the use of intoxicants in India. Kautilya's Arthasastra listed a variety of liquors such as Medaka, Prasanna, Asava, Arista, Maireya and Madhu. Caraka Samhita also mentioned sources for making various Asavas: cereals, fruits, roots, woods, flowers, stems, leaves, barks of plants and sugar cane. About 60 Tamil names were found in Sangam literature, which suggest that liquors were brewed in south India since the ancient times. Medieval alchemical texts also mentioned fermented liquors and their methods of preparation. Alcoholic liquors were classified into the following categories depending on their applications in alchemical operations:

Dasanapasani Sura: used in dyeing operations

Sarvacarani Sura: used in mixing operations of all kinds

Dravani Sura: used in dissolving substances

Ranjani Sura: used in dyeing operations

Rasabandhani Sura: used in binding mercury

Rasampatani Sura: used in distillation of mercury

Susruta-Samhita used the word khola for alcoholic beverages; perhaps the modern word alcohol is derived from it. A large number of alcoholic preparations were described in various texts.