Sunday, September 12, 2010

Blue Celery

Willow was given a science workbook, and in that science workbook she found perhaps the most ubiquitous science experiment among all science experiments: celery and colored water.

You will need:
  • leafy celery. This was actually hard to find, since it seems that most grocery celeries have the leaves cut off--my theory is that the leaves begin to spoil before the stalks, and so impedes the celery's shelf life. Next spring, we may try to grown our own leafy celery for science experiments.
  • liquid food coloring. For cooking and baking, I use professional-quality food coloring gel or paste, but liquid food coloring is often the best for crafting.
  • clear glass. We used a Mason jar.
1. Remove a leafy celery stalk from the rest of the bunch, and cut off the bottom half-inch or so with a sharp knife. I cut my stalk at a diagonal, to expose more of the stalk to the water.

2. Fill the glass jar 1/3 to 1/2 full of water, and dye it a dark color with several drops of food coloring. Blue and purple and even a dark red work well:
3. Set the celery stalk in the water, and let it sit all day.

As the celery stalk sits in the water, it acts like any plant, in that it draws water up into its leaves. Because this water is colored, very gradually, over the course of several hours, you will begin to notice spots of color in the leaves as the colored water reaches it. Over time, these spots of color will become larger and more numerous:
If you have a microscope, you can cut a thin slice off of the celery stalk to examine, and also a section of the smallest and thinnest of the leaves. The leaf section is especially dramatic at around 600x, at which magnification you can see the cells, but also very clearly the veins through which the blue water is traveling, now set apart from the green leaf in blue.

And now you may add to your mental picture of what our messy living room table looks like, a jar of celery sitting in colored water, for this experiment apparently often bears repeating.


Phyllis said...

I always like looking at the you can talk about how the "veins" in plants are called xylem, and that the xylem takes water and minerals from the roots to other parts of the plant. You can also tell them that there are other tubes in plants called Phloem, which take the sugars (the plant's "food") created during the process of photosynthesis to other parts of the plant.

stiner0305 said...

never thought about using celery! we have used queen ann's lace. but it takes forever it seems like. will have to go and find some celery now.

julie said...

Ooh, now I want to use queen ann's lace, too!

Must add xylem and phloem to the handwriting words this week--such tasty words!