 This is a desiccator. A desiccator is a closed system and normally you would have a desiccant, something in there to absorb moisture. We're using it as a closed system and it's just a glass container with thick walls and it has a smooth ground glass top that has an oil around that and that's what allows it to make an air tight container. Inside we have a beaker of distilled water and a beaker of a copper sulfate solution and you can see that we've marked them with the same level. So what we're going to do is observe what happens to the the liquids in each of these beakers over time. At the end of eight weeks you can see that there is no water in the beaker that was initially pure water and all of the water is in the copper sulfate beaker.