As a doctoral researcher, one of the “perks” has always been babysitting the undergraduates. I don't use that phrasing ironically. As a postgraduate demonstrator, you're not so much leading a laboratory as watching eighteen and twenty year olds working independently to make sure they don't set anything on fire – or put it it out quickly if they do. This leads to a very condescending demonstrator mentality, embittered by the disappointing responsibility for, if anything goes wrong, staying there later, probably alone with the same cack-handed student who initiated the disaster.

And it isn't so much their lack of practical skills (although the number of perished rubber tubes strewn across heating plates might seem to suggest another theory), as lack of reading skills. For example, I had one student who decided to cut some corners when it came to rinsing out equipment by filtering into the same Buchner flask twice and then throwing away the mixed waste from steps 1 and 2 of the lab. Unfortunately, he had failed to read beyond the line in step 2 which read “collect the product” to realise that whilst the product from step 1 was the solid, the product from step 2 was the liquid and would be needed for step 3. ...Which he had just combined with earlier waste. So, after a failed battle with the separating funnel, he was obliged to start all over again, steps 1 and 2 as well as 3. And during the last peaceful hour, whilst I sat on the far side of the lab bench watching him like a hawk, backed by the gentle music of his happily chuntering filtration, I explained to him why, even if he had been collecting a solid, not clearing out your Buchner flask was a bad corner to cut. A bit of suck back, and your solid ends up embedded in the sludge from earlier in the lab, contaminating it, or – the gut-wrenching horror of every undergraduate – messing with your yield. And that, I explained, is how you learn the most important skills you can acquire for practical chemistry: how to cut the right corners.