Indigenous Knowledge of Gunpowder Manufacturing in Assam: An Ethnochemical Study (Ahom Period)

 

Indigenous Knowledge of Gunpowder Manufacturing in Assam:
An Ethnochemical Study (Ahom Period)

 

 

Abstract

This study reconstructs indigenous gunpowder manufacture in medieval Assam by synthesizing fragmented Assamese manuscripts, oral traditions, and early foreign observations. Focusing on locally available alkalis — notably kola-khār (banana ash) and yakshār (black-cow urine derived alkali) — and the institutional framework (Khārgohāin / Khargariya Phukans and Khārghars), the paper interprets traditional practices through the lens of modern chemistry. It shows how potash extraction, nitrate-bed fermentation, charcoal production, and sulphur procurement combined to yield functional black powder used in Ahom artillery and muskets. The analysis highlights Assam’s sophisticated empirical chemistry, organized manufacture at scale (documented by contemporary observers), and the urgent need to record and scientifically study these nearly-lost technologies.

 

Keywords: Ahom Dynasty, Indigenous Technology, Gunpowder, Kola-Khār, Yakshār, Assam, Saltpetre (KNO₃), Khārghar, Ethnochemistry

 

 

 

1. Introduction

The adoption and local manufacture of gunpowder in Assam became prominent from the early 16th century, notably after the Dihingia Ahom king’s conquest of the Chutia polity (1497–1539 CE) and the acquisition of the celebrated “Mitha Holong” cannon. From rudimentary ash-and-lime fire-weapons, Assam developed a coherent technology of black powder manufacture supervised by specialized officials (Khārgohāin / Khargariya Phukans) and produced in state-organized workshops (Khārghars). This paper combines historical narrative with ethnochemical explanation to present a single, coherent account suitable for technical students and historians.

 

2. Historical testimony and scale of manufacture

 

2.1 Foreign observations

 

Jean-Baptiste Tavernier (Travels in India, 1676) provides a rare external testimony: Assamese gunpowder was fine-grained, effective, and manufactured under official supervision in designated workshops. Such testimony corroborates indigenous records of organized manufacture.

 

2.2 Documentary evidence of scale

 

Accounts from the Mughal campaigns report extremely large caches of powder seized from the region (e.g., Mir Jumlā’s retreat yielded documented tons and numerous containers), indicating industrial-level production under the Ahoms rather than mere household manufacture.

 

3. Raw materials: indigenous sources and preparation

 

3.1   Potash and saltpetre precursors: Kola-khār

 

It derived from the ash of Bhim banana stems and leaves. Stems were cut (traditionally in the month of Kāti), sun-dried, and combusted; ashes were leached with water, filtered, and the alkaline filtrate concentrated or dried into a powder. Banana ash is rich in potassium salts (primarily K₂CO₃ and related salts) — ideal feedstock for saltpetre formation.

 

3.2 Yakshār (Cow-urine derived alkali)

 

Prepared historically by collecting and drying urine in a dedicated cowshed over extended periods (accounts indicate months to a year), after which a white crystalline deposit on the floor was harvested. Indigenous descriptions emphasize that this deposit was neither Mushroom nor fungal growth but a crystalline alkali material, later processed for technical use. Yakshār supplied additional soluble alkali and organic nitrogen sources to nitrate beds.

 

3.3 Charcoal (Carbon, C)

 

Produced from soft woods and bamboo (locally abundant), selected to yield highly porous charcoal — the preferred fuel component of black powder. The porosity and surface area of such charcoals improve reactivity and burn rate.

 

3.4 Sulphur (S)

 

Sulphur does not appear to be locally abundant in Northeast India; historical practice likely relied on trade for elemental sulphur or extraction from mineral ores. Sulphur’s role is to lower ignition temperature and facilitate rapid, sustained combustion.

 

3.5 Biological nitrogen sources: urine, dung, and organic waste

 

Urine (rich in urea), animal dung, and decaying vegetation provided nitrogenous substrates that, under microbial action in nitrate beds, were converted into nitrites and ultimately nitrates (NO₂⁻ → NO₃⁻). Indigenous practice of moistening ash pits with urine and incorporating dung into nitrate beds accelerated this biochemical conversion.

 

 4. Nitrate-bed technology: ethnochemical process

  4.1 Principle

Potassium salts from ash (K₂CO₃, KCl, etc.) must be combined with nitrates formed from nitrogenous organic matter. Indigenous nitrate beds (composts or layered ash/organic refuse pits) hosted nitrifying microbial populations that oxidized ammoniacal nitrogen to nitrite and nitrate. Leaching and crystallization then produced crude saltpetre (KNO₃).

 

 

 

 4.2 Typical steps (ethno-technological reconstruction)

 

·            Ash collection & leaching: Burn banana stems → collect ash → leach with water → obtain potash-rich liquor

·            Bed preparation: Mix ash/soil with organic waste (dung, urine, decayed plant matter) in a designated bed/pit

·            Moistening & fermentation: Regularly moisten with urine and water to maintain microbial activity; allow months for nitrification

·            Leaching & crystallization: Periodically leach the bed with water; concentrate filtrate and allow crystallization of saltpetre

·            Refinement: Re-crystallize or dry to obtain refined potassium nitrate for powder manufacture

 

 

5. Black powder composition and combustion chemistry

 

5.1 Typical composition ratios (historical/technical range)

 

While local recipes varied, functional black powder compositions commonly fall into ranges approximating:

 

o   KNO₃                       : 60–75% (oxidizer)

o   Charcoal (C)         : 15–20% (fuel)

o   Sulphur (S)           : 5–10% (ignition facilitator)

 

Note: Exact historical Assamese ratios are not uniformly documented in surviving manuscripts; these ranges are presented as chemically plausible reconstructions informed by global black powder practice.

 

 5.2 Simplified reaction (idealized)

 

2KNO₃ + S + ³C → K₂S + N₂ + ³CO₂

 

 

o   Role of KNO₃       : provides oxygen to sustain rapid combustion.

o   Carbon                   : primary fuel converting to CO₂/CO and releasing heat.

o   Sulphur                  : reduces ignition energy and improves flame propagation; by-products include SO₂.

 

The rapid generation of gaseous products produces the high-pressure impulse required for propulsion in guns and cannons.

 

 

6. Institutional organization and socio-technical roles

 

o   Khārgohāin / Khargariya Phukans: designated officials responsible for procurement, oversight of Khārghars (powder workshops), quality control, and distribution to military units.

o   Khārghars (workshops): localized centers where ash processing, nitrate-bed management, powder mixing, and storage were carried out — indicating a division of labor and specialized craft knowledge.

o   Khargariya manuh (workmen): village or guild laborers trained in alkali preparation, ash leaching, nitrate crystallization, and powder blending.

o   Knowledge transmission: Technical vocabulary preserved in manuscripts reflects a systematic material taxonomy and process knowledge communicated across generations.

 

 

 

 7. Technological significance and broader impact

 

o   Empirical chemical engineering: Traditional practices embody processes equivalent to leaching, crystallization, microbial nitrification, and controlled calcination — an applied ethnochemistry.

o   Ethnobotanical selection: Preference for banana ash demonstrates material selection based on practical knowledge of potassium content and ash chemistry.

o   State-scale production: Documentary evidence of large seized quantities and foreign observation attests to organized, high-volume manufacture under state patronage.

o   Regional dissemination: Tavernier’s and other accounts suggest Assam may have been a node in the regional transmission of gunpowder technology to Southeast Asia.

 

 8. Decline, loss, and the need for scientific recovery

 

Changing political regimes, technological obsolescence with imported gunpowder technologies, and scant documentation led to rapid erosion of indigenous know-how. Many process details are now fragmentary, surviving only in scattered manuscripts and oral recollections. Systematic interdisciplinary work — combining archival research, experimental replication (ethno-replication under controlled safety protocols), and chemical analysis of extant archaeological/anthropological samples — is required to preserve and rigorously understand this heritage.

 

9. Conclusion

 

The material culture and documentary traces from the Ahom period reveal a technically sophisticated system for producing gunpowder that married local resources, biological processes, and institutional organization. Kola-khār (banana ash) and yakshār (cow-urine alkali) functioned as locally adapted feed-stocks for salt-petre production; charcoal and sulphur completed the triad necessary for effective black powder. Interpreting these practices with modern chemical concepts not only recognizes the practical intelligence of Assamese craftsmen and officials but also stresses the importance of conserving and scientifically investigating near-lost traditional technologies.

 

 

 

 

A. Appendix A — Glossary

 

Indigenous term	Transliteration / variant	Plain meaning / role	Modern equivalent	comment
1	2	3	4	5
Kola-khār	কলা-খাৰ	Banana alkali — ash/leachate from banana stems	Potash-rich ash; source of K⁺ (K₂CO₃, KCl traces)
Hiloi-khār	হিলৈ-খাৰ	Ash from plant matter (often banana)	Potash-bearing ash (feedstock for nitrate formation)
Javakshariya	যৱক্ষাৰীয়	Barley/cereal ash or alkali derived from cereals	Potash from cereal ash
Yakshār	যক্ষাৰ	White crystalline alkali deposit produced from dried cow urine / cowshed floors	Organic-salt deposit containing soluble alkali and nitrogenous residues (historical description)
Khārgohāin / Khargariya Phukan	খাৰগোঁহাই / খাৰঘৰীয়া ফুকন	Official in charge of Khārghar and alkali/nitrate production	Administrative/technical supervisor
Khārghar	খাৰঘৰ	Powder workshop / alkali production site	Workshop /           processing site
Khargariya manuh	খাৰঘৰীয়া মানুহ	Workers/guild responsible for alkali preparation and powder	Skilled labourers / craft guild
Mitha Holong	মিঠা হোলোং	Name of a celebrated cannon captured by Ahoms	Specific artifact (cannon) — historical referent

 

 

B. Table 1 — Raw material sources, indigenous names, modern chemical equivalents

 

Indigenous source / name	Traditional preparation (summary)	Dominant chemical(s) (modern terms)	Analytical methods to confirm composition
1	2	3	4
Banana ash            (kola-khār / hiloi-khār)	Burned banana stems → ash → leached with water → filtrate	Predominantly K⁺ salts (K₂CO₃, KCl, K₂SO₄ traces)	Ion chromatography (K⁺, Cl⁻, SO₄²⁻), XRD, ICP-OES
Barley/cereal ash (javakshariya)	Burn ash from cereals → leach	Potassium salts, some Ca/Mg	Ion chromatography, XRF
Yakshār                   (cow-urine deposit)	Accumulated/dried urine deposits → crystalline material	Organic nitrogen residues; potential ammonium salts; mixed alkalis	Elemental analysis (CHN), ion chromatography for NH₄⁺/NO₃⁻, FTIR
Charcoal           (bamboo / softwood)	Controlled low-oxygen carbonization	Porous carbon (amorphous), variable ash content	BET surface area, SEM, proximate analysis, elemental C/H/O
Sulphur (import/mineral)	Procured via trade / ore processing	Elemental S, sulfide/sulfate impurities	XRD, XRF, Raman spectroscopy
Urine / Dung / Organic waste	Used to fertilize nitrate beds / provide N substrate	Urea → NH₃ → microbial NO₂⁻/NO₃⁻	Ion chromatography, microbial community profiling (16S rRNA sequencing)