Flashback - Contamination

I think the most useful thing I learned from chemistry in college was cleanliness. The first day of chem. lab we were asked to fill our beakers with a clear chemical (I forget what it was) and then rinse each beaker until we thought it was clean. Some of us flushed our beakers 5 times or more – as expected most of the students rinsed only twice. The impromptu test was a drop of liquid administered by the professor that turned red in the presence of the material we were cleaning from the beakers. I have never forgot that lesson, or the threat of contamination in advanced materials testing.

Tomorrow I’ll explain what reminded me of this.