We had already read about the mummification process in several different library books on Egypt, so I wanted to take a different tack and look at the science behind how mummification works. Also, technically, I knew that the mummification process described in Chapter 4 of Story of the World was really not fully developed until the New Kingdom (though I don't know if I would have cared enough to tweak this if there hadn't been other reasons to).
For our alternative text we used a page from "Science of Ancient Egypt: Mummification" (part of a larger bundle on Ancient Egypt by Dr. Dave's science which I bought after falling in love with his free sample unit on The Nile). It covered some things that the other books we read didn't about the science behind making mummies.
You may notice that Unit is for 4th - 7th graders...and when we did this my son was a 1st grader with a Kindergarten sized attention span. So, why would I do a crazy thing like that? Well, because my son loves science, because this presents that science in an engaging way, and I had a feeling he would listen, even if he didn't understand absolutely everything.
I didn't try to cover the whole unit though, since I knew that would be an attention span stretch. In stead I used a couple of pages from it for this lesson, and I did what I always do...added some tactiles and visuals, and of course, lots of questions.
First, we reviewed Egyptian mummification with this video...
Then, before we dug into the text, I took my son outside to see something I knew had been sitting out by the fence in our yard...the remains of a dead bird. I knew it would be a great example of what happens to an animal after it dies...and how microorganisms take part in that process (though I'm sure ants took a part too).
I pointed out the bones and the beak and the feather, and asked my son "What do you think happened to the rest of it, all the bird's muscles and stuff?"
He gave a guess about the bird going to heaven (theology lessons pop up when least expected, don't they?).
"Well, the Bible doesn't say whether birds go to Heaven. Some people think they do, and some people don't, but we don't know. But when people go to Heaven it says God gives us new bodies...so our old bodies stay here when we die. So even if animals go to Heaven it doesn't mean their bodies do too. So what do you think happened to the bird's body?"
I let him give a couple more guesses and then said, "Lets go inside and find out!" That got him interested and he listened intently as I read the whole page on "Preserving the Body" which talked about how microorganisms break up and consume dead things and how the mummification process prevents that.
At that my son expressed some fears about microorganisms eating him...so I told him about how when we're living that our cells have ways of fighting bad bacteria and germs, and that other bacteria lives in our body and doesn't hurt us, but when someone or something dies than its cells die too, and so the microorganisms then start to eat the dead cells.
(Yeah, all that...it was all off the cuff and I wasn't sure if that was completely correct, though it did assuage his fears. Later I checked up on it and got this great answer from someone on Answers.com. I was pretty on target...but he gave some extra details that were really great.)
We skipped the next page to come back to after we had done our egg experiment (as it gives away the end), and read the first paragraph of "The Chemistry of Salt." This first paragraph talks about how salt is a mixture and how there are different kinds of salt (even baking soda is, chemically, a salt). So, I showed him some.
Aw, the salt looks like a funny monster face.
Click on it to see the different salts enlarged.
We looked at regular salt, coarse ground sea salt, Himalayan sea salt, Epson salts, and baking soda. I left these out on a dish for him touch and play with while I read the next paragraph about natron. When we got to the last paragraph about where the Egyptians got natron (in the Natron Valley, in the Nile Delta), we looked it up on our map.
Then, we did an experiment where we mummified a hard boiled egg. I've seen this done with apples too, or a whole chicken (as suggested in the SOTW Activity book).
- Hard boil an egg (or two if you want to have a "control" egg...see section below). Peel off the shell.
- Measure the egg with flexible tape ruler and write down results.
- Weigh egg and write down results.
- Mix an equal amount of salt and baking soda to make an approximation of natron (you can just use salt in stead)...enough to cover an egg.
- Put the egg in a cup or open container and cover completely with natron mixture.
- Uncover egg and repeat steps 1 - 3 every day for several weeks until the weight and size remains constant.
We also put another egg outside in an open container to see what happened to it (but did not measure it, because I knew after a while we wouldn't want to touch that one). In stead we took pictures.
Below are our pictures of our egg mummy (left) and control egg (right). OK, yes, that first picture is the same egg reversed...cause I didn't take a picture of the mummified one before we put it in the salt. It's not consecutive days because we didn't take a picture every day (the days shown are as follows: Day 1, Day 2, Day 5, Day 9, Day 12), and the sizes are not completely to scale, though I did try to show how they shrunk (it was a little more dramatic than the pictures here show, actually). But you can still get the general idea.
Click to see larger pictures.
(We missed taking a picture of the mummified egg that last day shown, but I thought the changes in the other egg were interesting). The control egg eventually withered away to nearly nothing and we tossed it. The mummified egg eventually turned rock hard and gray, but alas I didn't take a final pic. I left it outside and then forgot about it a long time and it was gone (guess it didn't stay forever, but we live in a humid area, not the dry Egyptian desert). Plus, some animal may have eaten it.
This was a fun lesson and my son really enjoyed it. I would recommend this experiment for any kids interested in mummies.
You can find this post on the Family Friday Link-up,