Exploring Mummification with Hot Dogs

Introduction

Have you ever seen or heard of the movies "The Mummy" or "The Mummy Returns"? Mummies have often played a part in nightmares for Western cultures, but in ancient Egypt, mummification was a serious religious ritual thought to be necessary for a person to enjoy the afterlife. In this activity, you will learn about the science behind the process of mummification by mummifying a hot dog.

Materials

• Ruler
• Scrap piece of paper and pen or pencil
• Piece of string or yarn
• Paper towels
• Airtight plastic storage box with lid. Box must be at least 3 inches deep and longer and wider than the hot dog.
• Meat hot dog
• Baking soda, approximately 3 pounds from unopened packages. You will need enough to thoroughly surround and cover the hot dog in the box. Baking soda is also known as sodium bicarbonate.
• Optional: Disposable gloves
  
  
  Image Credit: Teisha Rowland, Science Buddies / Science Buddies

What Happened?

Baking soda is a desiccant, which is a substance that dries out things next to it. It does this by absorbing moisture from its surrounding environment. The baking soda should have absorbed the moisture from the hot dog, desiccating it, or drying it out. (Fresh baking soda is needed because older baking soda will not be as effective, having already absorbed moisture from its surrounding environment.) As the hot dog lost moisture, it changed in color, smelled bad, and shrank. For different brands of hot dog you may see slightly different measurements, but for one of our trials we saw the hot dog become about 4% shorter and 25% smaller in circumference after one week.

Digging Deeper

A mummy is a corpse whose skin and flesh have been preserved by chemicals or by exposure to the elements of weather. It is thought that the ancient Egyptians believed that preserving the body was important for a person's afterlife. The oldest evidence of Egyptians performing mummification dates to about 3500 B.C. (although older purposefully mummified remains have been found elsewhere, such as ones dating to about 5050 B.C. in Chile). There were several steps to the Egyptian ritual of mummification that were important for preserving a body. After thoroughly washing the body in the waters of the Nile River, an embalmer would remove several internal organs from the body. This was important because internal organs are some of the first parts of the body to decompose. The body would then be stuffed and covered with natron to desiccate it. Natron is a naturally found salt mixture of desiccants that includes baking soda (sodium bicarbonate). Once desiccated, the body was rubbed with perfumed oils and then carefully wrapped with linen bandages. The remains were then placed inside of a sarcophagus, inside a tomb. In this activity, you get to play embalmer and mummify a hot dog using baking soda.

For Further Exploration

• Try this activity with different varieties of hot dogs. Do chicken hot dogs mummify faster than beef hot dogs?
• Although you mummified the hot dog for a week in this activity, the hot dog may still only be partially mummified. You could continue to mummify the hot dog, adding fresh baking soda and recording measurements and observations once a week for a few weeks until you do not see any more changes in the hot dog. How long do you need to repeat this mummification process until the hot dog is completely mummified?
• Investigate the different ways that ancient people mummified human remains, or that humans have been naturally preserved (such as with the bog bodies found in Northern Europe). How could you apply any of these techniques to mummifying a hot dog?

Related Resources

Project Ideas

Links

• Blog Post: The Pull of Ancient Egypt
• Blog Post: Success Story: Student Has Science Fair Success All Wrapped Up

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