I washed some apples and served them on a hand-carved soapstone platter (see photo). When we began to eat them, we noticed the apples had left blue stains on the plate. What could have caused this?

Tony Wills, London, UK

I washed some apples and served them on a hand-carved soapstone platter (see photo). When we began to eat them, we noticed the apples had left blue stains on the plate. What could have caused this?

Tony Wills, London, UK

Having discovered the joys of the "appletini" (vodka mixed with apple juice, cider or apple liquor) I have a question.

The garnish is a slice of apple and a Maraschino or glacé cherry on a cocktail stick. If the cherry is at the bottom of the stick it floats in the appletini, but with the apple slice at the bottom it sinks. Why? Surely the buoyancy of the two items combined is an absolute and their orientation should make no difference.

I shall leave it to the imagination as to the amount of 'tinis consumed before this anomaly became a burning conversation topic!

Richard Batho, St Saviour, Jersey

I once read that apple pips contain cyanide. Is this substantial enough to be harmful to humans who choose to eat all of the apple, including the core? If it's not a high content, then how many pips would you have to eat to feel the effects?

Similarly, do other fruits also contain harmful amounts? Stones from peaches and plums are much bigger than the pips in an apple...