Greek and Roman writers record the use of a substance called miltos as a decoration, a medicine - and a handy way to repair a boat. Now scientists have worked out why. Andrew Masterson reports. From ancient Greek and Roman source texts it is possible to conclude that in the classical world a mineral, a powder known as miltos, was something of a wonder substance. Miltos - referred to in the works of writers such as Theophrastus, Dioscorides and Pliny - was red, fine-grained, and made up mostly of iron-oxide. By the time Theophrastus, a Greek philosopher and proto-botanist, wrote...