I stopped on the side of the road on the way to work and got some ocean water in a cup. On the weekend I poured some water in watch glasses I borrowed from the chem teacher and put them in the oven, after trying to have the sun dry it for a few hours. Took them to school and did not show them to the students for a few days. It was super humid and the dried salts started to get wet as the watch glass collected water from the air like crazy. The only ones that were ok were the ones that were wrapped up and put in a container. So show them soon after you make them.
Sat, 02/02/2013 - 16:51
If you find (or a student creates) that micro-history, it would be great if you could share! I always like to share those kinds of connections with my students and ask them to delve into their own backgrounds for correlations, differences, etc.
Fri, 01/25/2013 - 20:10
I wonder if you could just boil off the water on the stove-top using mason jars that could be sealed once you were down to the salt? But, I still like the idea of letting the differential solubilities of the different salts make rings in shallow watch glass or bowl or something of our own design.
Next year, when we come around to this lesson, I want to weave in more about Hawaiian salt-making, the importance and uses of salt in Hawaiian and other cultures, and something about the entrepreneurs who have been marketing "gourmet" salts here and elsewhere. I wonder if anyone has written a micro-history on salt? Heck, that would make a good assignment for students.