Statistical analysis of the effect of high dilutions of arsenic in a large dataset from a wheat germination model
M Brizzi, D Nani, M Peruzzi and L Betti
This paper describes the statistical analysis of a series of experiments using a simple
biological model (wheat germination in vitro), where a large number of wheat seeds
were treated with homeopathic potencies of Arsenic trioxide. Some potencies, such as
As2O3 40x, 42x and 45x, have repeatedly shown a signi®cant stimulating effect on
germination compared to controls, whereas As2O3 35x has a signi®cant inhibiting effect.
In some experiments the seeds were stressed before the experiment with a sublethal
dose of the same substance. We performed a statistical analysis, both for stressed and
non-stressed seed groups, using Poisson distribution as a suitable model for representing
the number of non-germinated seeds in a standard experiment with 33 seeds in the
same Petri dish. Finally, we have considered the most repeated potencies (30x and 45x),
computing the sample odds ratio (OR) and a 95% con®dence interval (CI) for the
population OR. Our results show signi®cant reproducible effects of some As2O3 decimal
potencies, particularly As2O3 45x. In stressed seeds, even decimal potencies of water
seem to give signi®cant results compared to control, whereas high dilutions of As2O3
without potentization never show signi®cant effects. British Homeopathic Journal (2000)
89, 63±67.
Keywords: plant models; in-vitro germination; arsenic trioxide; Poisson distribution; odds
ratio