A homeopathic remedy that uses tiny amounts of arsenic could cure stomach cramps, according to European research.

Roger Harrabin explains how homeopaths use arsenic

Homeopaths who say an infinitesimal quantity of arsenic shaken in several dilutions of water cures diahorrea may be right, say Dutch scientists.

The technique uses the similia principle - the idea that poisons that produce vomiting and stomach cramps can reverse the symptoms when heavily diluted.

The theory has been ridiculed by many orthodox doctors. But research at the University of Utrecht in Holland suggests there may be something to it.

Researchers took cells from a pig's liver and poisoned them with arsenic. They then treated some of them with a homeopathic dose of one part arsenic to a million parts water.

Dr Roeland van Wijk, who led the research, said: "The homepathically treated cells recovered better."

Recipe for success?

This idea that a miniscule dose of the original poison helps an organism recover was established by the founder of homeopathy, Hahnemann, in the 18th century.

Another of his propositions is harder to swallow - that a remedy can work at dilutions so weak that there is no chemical trace of the original substance left at all.

Professor Colin Blakemore is not convinced

Professor Colin Blakemore, professor of physiology at Oxford University, said: "That would overturn all our notions of physics and chemistry because if a substance is to have an effect in a chemical reaction there actually has to be some of it there."

However, technology might offer clues as to how a medicine without an active compound could work.

Tony Scott Morley, an alternative practitioner in Dorset, says he can test the electrical conductivity of a patient's acupuncture points using a probe.

If the machine shows a high reading, he says it means abnormal skin conductivity at that point. Scott Morley then pops a homeopathic remedy into another part of the machine and the signal from the probe appears to be smoothed out.

He said: "A homeopathic remedy is a pure signal like a radio signal, locked into water."

Shaken water theory

Conventional doctors reject this theory, but physicists have demonstrated that shaken water molecules can arrange themselves into semi-solid structures at room temperature. These crystals can also carry an electrical field.

Professor Benjamin Bonavida explains what his findings show`

Professor Benjamin Bonavida of UCLA medical school in Los Angeles tested a sample of the crystals on blood and found an effect on the production of cytokines, which affect the body's immune response.

He said: "When we use this water preparation as compared to controlled laboratory water preparation, we can demonstrate that we have an early induction of cytokines."

He remains sceptical about his results because the makers of the test sample refuse to tell him exactly what is in it. They say it is commercially confidential.

If the tests are ever independently verified homeopaths will celebrate - the energy field discovered by physicists in shaken water was first suggested by Hahnemann 200 years ago.