Letter: Physical ability

DIAMONDS and graphite are both made of carbon, but their atoms are arranged differently and the two substances behave very differently. The water in homeopathic remedies may also behave differently as a result of having its constituent atoms arranged differently from ordinary water. The argument that high-dilution homeopathic remedies cannot be effective since few molecules of the original substance are left ('A natural health service', Review, 4 July) ignores this possibility.

Brian Josephson

Professor of Physics

University of Cambridge