London buses and great expectorations | Brief letters

The concept of poor behaviour as perpetrated by those perceived as “other” is not just a contemporary problem (Suzanne Moore, G2, 23 February).Until I pointed out that London buses displayed notices informing passengers that expectoration was prohibited.• When I was a schoolboy, not only did the chemistry sets on sale in toy shops contain bottles of acids but they could be refilled at the chemist’s without question (Acid is all too readily available in the UK, Letters, 17