The phrase a trout in the milk denotes highly convincing circumstantial evidence, especially of a hypothesis otherwise difficult to prove.
This phrase occurred, for example, in Mr. Murdoch’s loan, published in The Washington Star (Washington, District of Columbia, USA) of Monday 12th May 1980:
On the face of it, Export-Import Bank President John L. Moore Jr. was flooring the throttle to encourage foreign purchases of American-made products when he sought quick approval for an unusually favorable loan to entrepreneur-publisher Rupert Murdoch. The approval was to help Mr. Murdoch make up his mind to purchase Boeing jets, instead of the European Airbus, for the Australian airline he controls.
But the Senate Banking Committee is skeptical about the face of it all, as well it should be.
[…]
What we have is a classic trout-in-the-milk situation of suspect circumstances.
The phrase a trout in the milk refers to the practice of surreptitiously diluting milk with stream-water. This practice was mentioned—and a trout in the milk occurred—in the following extract from an account of the weekly meeting of the Limerick Board of Guardians that was held on Wednesday 23rd April 1851—account published in The Limerick Reporter and Tipperary Vindicator (Limerick, County Limerick, Ireland) of Friday 25th April 1851:
The Chairman was then about opening tenders for supplying milk for the next six months, when
Mr. James Clampett said that he visited the William-street Workhouse last week, and he found there milk supplied by the present contractors, which was not fit for human beings; and he suggested that they should be visited with summary punishment as an example to all future contractors. The names of the contractors were—Fitzgerald, Lane, M‘Cormick, and Halloran.
[…]
Mr. Clampett stated that the milk supplied by Halloran was something better than the others; but at the same time it was very thin.
[…]
Twenty-four tenders for milk were then opened, at prices varying from 4d to 4½d per gallon.
Dr. Gibson observed that they had not charged for the water (laughter).
Mr. Gloster—Sure Mr. M‘Inerny, the Master, got a trout in the milk the other day! (loud laughter).
In the sense of highly convincing circumstantial evidence, the phrase a trout in the milk is ascribed to the U.S. poet, essayist and philosopher Henry David Thoreau (1817-1862).
It was the U.S. poet, essayist and philosopher Ralph Waldo Emerson (1803-1882) who credited Henry David Thoreau with this coinage in Thoreau, a biographical sketch first published in The Atlantic Monthly. A Magazine of Literature, Art, and Politics (Boston, Massachusetts, USA) of August 1862 (Thoreau died in May 1862)—this is the relevant passage from this biographical sketch:
I subjoin a few sentences taken from his [i.e., Thoreau’s] unpublished manuscripts, not only as records of his thought and feeling, but for their power of description and literary excellence.
“Some circumstantial evidence is very strong, as when you find a trout in the milk.”
“The chub is a soft fish, and tastes like boiled brown paper salted.”
“The youth gets together his materials to build a bridge to the moon, or, perchance, a palace or temple on the earth, and at length the middle-aged man concludes to built a wood-shed with them.”
[&c.]
The earliest mentions of the phrase ascribed to Thoreau that I have found are as follows, in chronological order:
1-: From Glorying in the Goad, published in The Atlantic Monthly. A Magazine of Literature, Art, and Politics (Boston, Massachusetts, USA) of July 1864:
The honest farmer is no more common than the honest merchant. He abhors the tricks of trade, he has his standing joke about the lawyer’s conscience: but the load of hay which he sold to the merchant was heavier by his own weight on the scales than at the merchant’s stable-yard; the lawyer who buys his wood, taught by broad rural experience, looks closely to the admeasurement; and a trout in the milk Thoreau counts as very strong circumstantial evidence.
2-: From Thoughts by eminent Thinkers, published in The New South (Port Royal, South Carolina, USA) of Saturday 8th October 1864:
—A ruler who appoints any man to an office, when there is in his dominions another man better qualified for it, sins against God and against the State.
—Some circumstantial evidence is very strong, as when you find a trout in the milk.
3-: From The Marysville Tribune (Marysville, Ohio, USA) of Wednesday 2nd November 1864:
Confucius said: To know that we know what we know; and that we do not know what we do not know, that is true knowledge.
Some circumstantial evidence is very strong, as when you find a trout in the milk.
There may or may not be an implicit reference to the phrase ascribed to Thoreau in the following anecdote, published in the Boston Daily Evening Transcript (Boston, Massachusetts, USA) of Thursday 10th January 1867:
A True “Fish Story.” Some time ago, the proprietor of the best hotel on New York Island was called to the pantry belonging to his house by the steward, who had become rather nervous about a noise, or rather a rapping, that was going on inside one of the well-filled milk-cans, that had a few moments before been delivered by the milkman. Of course no one could divine what the noise was caused by, and one of the Irish laborers offered the only suggestion, and that was that “sure he didn’t know, and maybe it’s the divil or some of thim sparyitural knockers.” As this did not seem conclusive, and as the can was being carefully emptied of the milk, (the Irishman standing ready with a dusting brush to defend himself,) a good-sized brook trout was discovered to be the spirit that had caused the tempest in the milk pot, and on being laid out, was suspiciously viewed by the hotel-keeper, who desired some one to tell him how that spotted young gentleman got into the milk; whether he was “poured in” during a process of watering, or whether it is the habit of the Dutchess county cows to “give” such things. He could not believe that old farmer was a cheat, or that his “cattle needed shingling,” (as Mumps remarked,) but he boldly asserted one idea, and that was that he intended to find out, satisfactorily, all about it.
As the head cook bore out the gasping brookling, several ideas were advanced, and some of the more scientific individuals suggested that there must have been considerable water in the milk, as it was impossible for a fresh-water fish to live in and respire cow’s milk. This is a question that remains open, and may be settled when the old farmer, who sends his milk to market in the same kettle with his brook trout, informs the public, not how “the milk got into the trout,” but how the trout got into the milk.
The earliest occurrence that I have found of a trout in the milk used as an independent phrase—i.e., without reference to the text ascribed to Thoreau—is from the transcript of a lecture by the Reverend John W. Chadwick on the resurrection of Jesus, published in The Brooklyn Daily Eagle (Brooklyn, New York, USA) of Monday 1st March 1880:
That God should send an angel to hasten the disciples to Galilee to meet Jesus there, and that afterward they should see Him in Jerusalem, gives God the appearance of a person who does not know his own mind, or the angel the appearance of not being well informed. This story must have been first current when an appearance in Jerusalem was no part of the tradition. But, from beginning to end, the story is a tissue of improbabilities, to use no stronger word. We have an angel with his appearance like lightning and his raiment white as snow. Now, an angel in a story is as sure a proof that
THE STORY IS A LEGEND
as a trout in the milk that the milk has suffered from adulteration.
word histories 