In 1968 Dr Richard Armour wrote an essay in JAMA in which he pretended to have found an old book, “being a study of certain curious categories of physicians.” There were four types. Firstly, the Ebullient, outgoing, exuding optimism and good cheer, backslapping, always encouraging and minimising his patients' illnesses. Next, the Lugubrious, entering the sickroom with a pained look like an undertaker coming to remove a body, speaking in a low sepulchral tone and always guarded about the outlook. Then the Fussbudget, meticulous to the extreme, even checking his stethoscope before using it, ordering every possible test and keeping elaborate notes on every detail, his files overflowing, his waiting patients growing weak while he completes his first physical examination of the day. Finally, Dr Speedy, always looking at his watch, notes in shorthand, counting the pulse while looking at the tongue, never sitting down, always on the move.

During my medical school days I also had an old book. It was a real one, bought on an impulse, written in French by no doubt a distinguished member of the academy. I never read much of it, but after graduation I took it on a Pacific cruise and in an expansive mood after an all-night party threw it overboard. It rests at the bottom of the ocean somewhere between Suva and Noumea, where generations of Francophone fish have come to appreciate the interesting approach of starting each chapter with brief introductory vignettes on “what to do” and on “what not to do.”

In former days the warnings of “what not to do” were against such things as administering creosote to consumptives or arsenic for gonorrhea. Now they might be against giving intravenous calcium to patients being given digitalis, morphine to patients with asthma, pethidine to patients receiving dialysis, or amiloride to patients with renal insufficiency.

More on the domestic side, you might add a warning against not heating water in a microwave unless you put in the cup something non-metallic such as a wooden stir stick or a tea bag. Otherwise there could be a build-up of energy, such as happened recently to a young man who sustained severe facial burns and was blinded in one eye as hot water blew up in his face. The doctors at the hospital said that they had seen several such cases, and accordingly emphasised this important “what not to do” warning.