Mary McKeown’s flowerbeds (Letters, 15 July) are subject to the same phenomenon that affects Chesil Beach and packets of muesli. In pharmaceutics (a branch of pharmacy) it is called demixing. A force applied to a heterogeneous mixture (gravity, wind/tide and shaking without inversion respectively in the examples above) will tend to separate diverse elements. Smaller soil particles “fall through the holes” between the stones. Lighter pebbles move further along the beach. Heavier grains of cereal end up at the bottom. It is a problem in medicine because it reduces homogeneity, consistent potency and, therefore, the safety of a mixture.
Unfortunately, it is also a factor that this government needs to urgently recognise: the stress of extreme austerity measures drives apart people of differing resilience, and the signs are that it could soon threaten the stability of society.
Peter Lowe
Newcastle upon Tyne
• Have an opinion on anything you’ve read in the Guardian today? Please email us your letter and it will be considered for publication.
