A STORY ABOUT ZINC
One of the best-known stories of zinc is in Primo Levi’s “The Periodic Table”, a wonderful book of short stories based around Levi’s chemistry experiences whilst studying for and during a career as an industrial chemist. This short description cannot do justice to Levi’s beautiful writing, but hopefully provides a flavour.
In this short story about zinc, Levi has just graduated from being one of 80 university freshmen to having the status of being allowed into the Preparation laboratory. This was his first exposure at university of being taken away from books and written chemical studies and being initiated into the real art of practical chemistry. Levi found this a rather brutal experience, since little guidance was given by his professor, and students were left to learn from bitter experience – it was “sink or swim” and, probably intentionally, only those who persevered, survived. On his first day in the Preparation laboratory, Levi was given the task of preparing the chemical zinc sulphate (ZnSO4). On paper this was simple: attack a piece of zinc with diluted sulphuric acid and then concentrate the solution and crystallize out the solid crystals. First he re-learned the lesson about diluting sulphuric acid – the acid must be added to the water, not the reverse, otherwise it is “prone to wild rages”. Next he learned a lesson about zinc that, whilst zinc is in theory readily attacked by sulphuric acid, if it is very pure nothing happens and the reaction is inhibited. Levi describes how “some salt and mustard” are needed, in this case a few drops of copper sulphate, and then the zinc will “wake up”.
Levi describes zinc as an element that is grey and boring. Indeed, this is exactly what zinc is: a boring metal that, in the right applications, does a beautiful job as an unsung hero. But Levi’s stories in “The Periodic Table” go much further than describing his experiences in a laboratory, weaving together interesting chemistry experiences with his story about life and about people. In this particular story he builds a bridge between himself and Rita, another student who, later that day he accompanies on her walk back to her home, after leaving the results of his attempts to crystallize his zinc sulphate to their own fate.