Knowing the vicissitudes of medical research, I expected a fair number of flashes in the pan and flies in the ointment, but neither is a common metaphor in PubMed.

I had somehow thought that flash in the pan came from gold-mining: the miner, as he swilled water around his pan, being deceived by the flash of something that was not the sought-after gold. But it is nothing to do with mining; flash in the pan originated in the 18th century describing the firing of the priming in a flintlock musket, without the musket firing its ball. From that, it has come to mean an abortive effort or outburst, or something that promised much but gave little. Searching on flash and pan has just 21 results, but only 7 are to flash in the pan. Five are asking if a new phenomenon is the way to the future (e.g. metobonomics, a particular application of endoscopic stents, systems pharmacology), and one is deciding that off-pump coronary artery bypass grafting is here to stay. The remaining one has inverted the metaphor, describing the use of fluorescence to detect amyloid proteins.

The other flashes and pans were spurious, such as flash bleach and pan-retinal, flash heat and an aluminum pan [US usage], and menopausal flashes [again US usage: British is flushes] and an author named CH Pan.

Fly in the ointment—in that wording—is also of 18th century origin, but there was reference to flies and ointment in the King James bible. A fly in the ointment is a problem or a drawback (qv), but it’s a bit more than that: the implication is that something is almost perfect, but that an otherwise small flaw probably means a rethink or a different approach. There are 14 fly (or flies) in PubMed—I can’t say how many of the flies reflect the small nuance beyond the simple problem. There are a few more that are literal flies, and one that is literal ointment as well: A fly in the ointment: evaluation of traditional use of plants to repel and kill blowfly larvae in fermented fish.

A fly in the ointment is not as bad as a spanner in the works, of which there are half a dozen. None reflects the human overtones of the phrase: that throwing a spanner (to Americans, a wrench) is a deliberate act. And one inverts the metaphor even more deliberately than for detecting amyloid: the Spanner is a temporary urethral stent to relieve urinary retention.

Neville Goodman is a retired consultant anaesthetist and a writer. He is co-author of a book on medical English.

Competing interests: I have read and understood BMJ policy on declaration of interests and declare that my only competing interest is my co-authorship of a book about medical English.