Today is the 150th anniversary of a historic operation performed by this surgeon - George William Callender. Few people know his name now, but Callender was once described as the first person to operate on the human heart. Callender was born in 1830 in Bristol and won a scholarship to St Bartholomew's Hospital in London. Smart both intellectually and sartorially, he amused the other students by always insisting on changing into evening dress for dinner - even when dining alone.

There's a lot of stuff on Twitter at the moment about Covid-related science communication, good and bad.

So this seems a good time to share a interesting example of a scientific urban myth that I've just come across. Here's a short THREAD. On my morning walk I was listening to a 2013 edition of @BBCRadio4's reliably funny panel show The Unbelievable Truth. At one point in this programme, the presenter @RealDMitchell's script asserts that:

Cardiac surgery is 125 years old today! On September 9 1896, the German surgeon Ludwig Rehn performed the first successful operation on the human heart. Born in Allendorf, Germany, in 1849, Rehn had an unusually varied career. While working as a GP near Frankfurt he noticed that workers at a local chemical works were prone to bladder cancer - deducing that the cause was a chemical they worked with, aniline.

How did Alexander Graham Bell and Wilhelm Roentgen contribute to a historic surgical operation that took place 125 years ago next month? Here's a THREAD about a presidential assassination, the inventor of the telephone, and the evolution of medical imaging. The story begins on July 2 1881, when President James Garfield was shot at point-blank range while waiting for a train in Washington D.C. His attacker was immediately arrested, but the President was gravely wounded.

Just stumbled across some fantastic photos of the RAF Symphony Orchestra's 1944-5 tour of the USA. Including my dad, aged 24, who played the flute in the orchestra and the RAF Central Band throughout the war. @RAFMusic Standing to the left of my dad is, I think, the celebrated horn player Dennis Brain, taking a photo of his own.

This historic document is the first electrocardiogram (ECG), recorded in 1887 by the British physiologist Augustus Desiré Waller. By the 1880s, experiments had already shown that electrical activity played an important role in cardiac function. In 1878 John Burdon-Sanderson demonstrated the sequence of tissue depolarization and repolarization that accompanied the beating of a frog's heart.

A few years ago a 59-year-old man walked into a hospital in eastern France and asked to see a doctor. He had no symptoms, but said he had been advised to get an X-ray. This is it: A lateral view gives a slightly clearer view of a foreign body in the lower lobe of the left lung. What could it be?