The Undercover Scientist, By Peter J Bentley

Bentley explains a conundrum regularly impressed on any (non-bearded) man who cuts himself shaving: why won't a razor cut stop bleeding? "Your skin has a remarkable blood supply that allows you to cool down by dilating vessels close to the surface. It's why you might go a bit red in the face after running."

Platelets in the blood will bind the cut "quite invisibly" if you press on it for 20 minutes. Other everyday mysteries explored by Bentley include the agony of chilli juice in the eye (it fools sensory cells into believing they have encountered heat), the ineradicable nature of red wine (it is a natural acid dye with a strong affinity to fibres like wool and cotton) and the propensity of milk to sour (natural bacteria eat the lactose, which turns the sugar to acid).