I remember being taught in biology class in our 1950s grammar school in Manchester that peristalsis works both ways (Dairylea cheese ad showing child eating while upside down banned over choking risk, 19 January). Under teacher supervision, two of us held a boy upside down by his ankles while he drank half a bottle of milk through a straw. We all survived the demonstration.
Dr Roger Merry
Keynsham, Somerset
• Lovely to hear the history behind the Gypsy Queen (Letters, 17 January). My housemates and I were still riding the Gypsy Queen from our student house to classes at Durham University in 1976.
Judith Jesch
Nottingham
• Non sibi sed was the motto of the then grammar school, Whalley Range in Manchester, which I attended between 1947-54. Now an academy, the motto is “Aspire, believe, achieve”. Sign of the times?
Janet Hurrell
Winchester
• Every day on my walk, I meet a number of “big dogs”. They are intelligent, honest creatures. Please stop demeaning them (‘Operation Save Big Dog’: who is in the line of fire at No 10?, 16 January).
Dick Tuckey
Ipswich, Suffolk
• If I were asked of what, in my country, I could be proud, I would say the NHS, the BBC and our network of public footpaths and associated Ordnance Survey maps.
Jojo Goodfellow
Wolvercote, Oxfordshire
• Six letters have torn this country apart: Brexit (Letters, 18 January).
Paul Tattam
Chinley, Derbyshire
• Have an opinion on anything you’ve read in the Guardian today? Please email us your letter and it will be considered for publication.
