A kettle of fish
There are a number of variants of this rather odd expression, principally differentiated by the addition of adjectives such as fine or pretty, indicating a bit of a muddle, or a whole new suggesting a completely new state of affairs.
It would seem that at least in the area around the river Tweed it was customary in the 18th century, at outdoor feasts to cook fish, principally salmon, in a kettle. Thomas Newte records this custom in his A Tour of England and Scotland, published in 1785, thus: “it is customary for the gentlemen who live near the Tweed to entertain their neighbours and friends with a fete Champetre (essentially an outdoor banquet) which they call giving a kettle of fish…a fire is kindled and live salmon are thrown into boiling kettles”.
We are not talking about kettles used to boil water for a nice cuppa but long saucepans which had been used over the centuries to cook fish in. You can imagine during the cooking process or perhaps after the flesh had been consumed that there would be a mixture of skin, bones and other remnants of the fish at the bottom of the pan. This may be the origin of the association of a kettle of fish with a mess or a muddle but this is by no means certain. What we do know is that the phrase was used figuratively some time before Newte’s description of the practice.
Henry Fielding in his History of the Adventures of Joseph Andrews, published in 1742, wrote, “Here’s a pretty kettle of fish, cries Mrs Tow-wouse” and “A rare kettle of fish I have discovered” in The History of Tom Jones, published seven years later. Francis Grose’s invaluable Dictionary of the Vulgar Tongue, published in 1811, gives incontrovertible proof of the figurative sense of our phrase. “When a person has perplexed his affairs in general, or any particular business, he is said to have made a fine kettle of fish of it”. So there we are.
A different kettle of fish is a different kettle of fish altogether and is a much more modern phrase, first appearing in the 1920s.
Butter wouldn’t melt in his mouth
Those who are keen to get down with the yoof call things cool, meaning impressive or great. This phrase gives the concept of coolness a slightly more pejorative meaning. Butter melts with the application of heat or in warm conditions and the breath from the mouth is generally warmer than the prevailing external air. So the inability to melt butter in your mouth is suggestive of a degree of coolness. A person so described is generally someone who is meek and mild or has the appearance of being good.
The phrase can be found in print as far back as 1530 and perhaps the most famous usage of it in a pejorative sense is to be found in Dickens’ Martin Chuzzlewit, where, in describing Mr Pecksniff, the novelist wrote, “It would be no description of Mr Pecksniff’s gentleness of manner to adopt the common parlance, and say that he looked at this moment as if butter wouldn’t melt in his mouth. He rather looked as if any quantity of butter might have been made out of him, by churning the milk of human kindness, as it spouted upwards from his heart.” I couldn’t have put it better.