Lesson 3 Chemistry in Society

Historical Examples of Uses of Chemicals

© flickr.com CC2.0
B3.2 Hide being prepared for processing

Before the dawn of modern chemistry, humans utilized chemical substances and chemical reactions, even though they did not fully understand the principles behind the events.

Indigenous Canadians used many chemical substances and reactions to enhance their way of life; for example, the process of brain tanning. Rawhide is by nature hard and not waterproof. It can be made into various items, such as whips, drums, string, and even casts for broken bones. However, by chemically reacting the rawhide with materials such as brains and smoke, you can create a soft, pliable, waterproof material known as buckskin. Buckskin can be used to make clothing, blankets, and shelters.

  Watch This

Tanning @ the Musée Régional de la Côte-Nord  https://quick.adlc.ca/tanning

This video is in the Innu language (there is a transcript provided). It shows the processing brain for tanning hide.

Other uses of chemical substances included

• animal fats and petroleum products used as waterproofing materials and as sources of fuel for heaters and lamps
• plant material such as blueberries, cranberries, lichen, indigo, and delphinium used as dyes for adorning fabric and porcupine quills
• many plants used for medicinal purposes, such as
• the leaves and flowers of wild roses being used to make tea to treat bee stings, colds, and diarrhea
• the flowers and leaves of yarrow are used to treat headaches, as a local anesthetic, as a coagulant (to stop bleeding), to aid digestion, and to help eliminate cold/flu by causing perspiration
• Echinacea is used to treat viral infections,
• lamb’s quarter is used as an antispasmodic to treat epilepsy
  
• balsam fir being used as an antiseptic
  
• cranesbill being used as an astringent (a substance that causes body tissue such as skin to contract)
  
• other medicinal plants
  

Some Indigenous cultures within Canada used fermented materials that have acidic properties to etch seashells, which are composed of calcium carbonate (this utilizes an acid-base reaction.) Other tribes mined copper ore and, using very hot fires, purified and annealed it, making it stronger. Ash from fires, which is alkaline (or basic), was used for many purposes, including making detergents and tanning hides. As you can see, the list of applying chemical principles to enhance their lifestyle is long!

© Wikimedia Commons
B3.3 Mi'kmaq birch box adorned with dyed porcupine quills

© Wikimedia Commons
B3.4 Yarrow

  Digging Deeper

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© Wikimedia Commons
B3.5 Wild rose

There has been a resurgence of interest in traditional Indigenous knowledge, such as identifying plant species that are native to Alberta that had significance to traditional Indigenous life. You can start investigating this fascinating topic on this website. https://sites.google.com/a/ualberta.ca/our-garden/our-plants

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The following website provides a listing of traditional natural quill dyes and mordants. http://www.nativetech.org/quill/dyes.html ;

Learn More

  Read This

  Practice Questions

1. Identify the importance of food preservation and list two historical methods of preserving food.
   
   
   Check your work.
   

   Fresh food is not available to everyone all year long, so preserving food as it is harvested is vital. Historical methods include drying, cooking, salting, fermenting, and smoking.
2. What is annealing, and why was the discovery of this process important?
   
   
   Check your work.
   

   Annealing is the process of heating a metal, which causes the properties of that metal to change. It is important because it allowed Indigenous people to create stronger tools.