Indigenous Chemistry
Modern scientific analysis has shown that Aboriginal and Torres Strait Islander Peoples have inhabited the continent for over 65,000 years, making them the longest living continuing culture in the world. Throughout this time, Australian First Nations acquired empirical knowledge of their natural environment using observation and experimentation, and applied this to solve complex problems and maximise resources. Therefore, in Australia we can be proud of one of the longest traditions of Indigenous science, which includes astronomy, physics, biology but also chemistry.
Historical records show that Aboriginal and Torres Strait Islander Peoples developed a sophisticated understanding of various chemical transformations, which they used to generate commodities that were either scarce or unavailable. Pigments for paints were produced through the controlled heating of gypsum for its calcination into fine white powders. Similar processes were employed to generate plaster used in the production of toys and games, as well as body ornamentation.
Image: White, yellow and red painting at Burrunggui, Kakadu. Rae Allen/Flickr, CC BY-NC-SA
Fermentation processes with Australian yeasts and bacteria were developed for the production of alcoholic beverages. This included fermented cider gum, a Eucalypt found in remote parts of Tasmania which produces a sugar-rich sap and that was sourced by local Aboriginal people for this purpose. Another known example is the fermentation of nectar-laden flowers (e.g. Banksia) that were steeped in water for varying lengths of time to change the sensory properties of the beverage.
Charcoal was produced through pyrolysis for use in pigments but also as an additive in adhesive resins. Pyrolysis was also employed to obtain desired inorganic materials from the organic matrix of plant matter. Aboriginal Peoples living far from the sea employed controlled pyrolysis of plants with a high sodium or potassium content to obtain wood ashes that could substitute sea salt. First Nations Peoples also generated quicklime from the pyrolysis of plants that were rich in calcium oxide. This was then used as an alkali to increase the effectiveness of medicinal plants. Pyrolignious acid, generated through pyrolysis, was used in the processing of marine shells into fine necklaces.
Finally, the combustion of resins obtained from a range of plants were used in torches to carry fire and importantly in Indigenous land management through controlled burning of Country.
Sources and further reading:
https://australian.museum/learn/first-nations/indigenous-science/
https://theconversation.com/pigments-and-palettes-from-the-past-science-of-indigenous-art-35604
https://theconversation.com/the-art-of-healing-five-medicinal-plants-used-by-aboriginal-australians-97249
https://www.adelaide.edu.au/news/news88682.html
https://australiancurriculum.edu.au/TeacherBackgroundInfo?id=56821
Cultural Burning
Cultural burning has been practiced by Aboriginal Peoples for millennia and is a key aspect of Indigenous land management. With intimate knowledge of Country, the appropriate time to burn the landscape in a controlled manner can be identified from environmental indicators including but not limited to soil quality, breeding behaviour of animals, the time at which certain flowers blossom and the particle nature of trees. Using controlled burning with low intensity fires, bio-mass can be cleared and new growth encouraged for kangaroos and other grazing animals.
Image: Victor Steffenson ABC "Fighting Fire with Fire"
Colonisation brought with it a European approach to agriculture, which conflicted directly with Indigenous fire-stick farming practices. The introduction of cattle and rabbits also had a severe impact upon fragile Australian soil systems, leading to a decrease in the presence of native crops and carefully managed cross lands. Furthermore, in the absence of cultural burning, bio-mass has greatly accumulated, contributing to the high-intensity and destructive bushfires of recent years.
Since these recent catastrophic fires, interest in fire-stick farming as a preventative bushfire measure has grown significantly. Organisations like the Firesticks Alliance Indigenous Corporation work with communities and fire-fighting organisations to inform about cultural burning to revitalise Country and drive change.
Chenery, S. & Cheshire, B. 2020. Fighting fire with fire [Online]. ABC News. Available: https://www.abc.net.au/news/2020-04-13/how-victor-steffensen-is-fighting....
Firesticks Alliance Indigenous Corporation. n.d. Our Approach [Online]. Available: https://www.firesticks.org.au/about/aboriginal-engagement-principles/ [Accessed].
Heath, N. 2021. Firestick farming: how traditional Indigenous burning protected the bush [Online]. Available: https://www.sbs.com.au/topics/voices/culture/article/2021/03/17/firestic... [Accessed].
