The chemical reaction of Cavendish involving zinc would be a reaction between hydrochloric acid and zinc yielding zinc chloride and hydrogen gas.
2Zn + 2HCl = 2ZnCl + H2
This is an example of a single replacement reaction where zinc replaces hydrogen in the acid molecule.
zinc + hydrochloric acid → hydrogen + unknown substance(s) in the flask
This was the answer straight from Plato. I hope that this helped you, please mark me the brainiest, like and rate my answer if it did! :)