on a similar note about food.when i was at school 25 yrs ago we had chocolate concrete and the only way to eat it was get your spoon and attack it like a hammer drill.good fun when bits pinged off on to other tables.i also remember we had big jugs of water on the tables and they were topped up between sittings.some kids used to spit in them ready for the next sitting which was terrible as i would never had done that coz it would just be wrong 
