a canary in the coal mine redux

expression o’ the day:
“a trout in the milk”

“Some circumstantial evidence is very strong, as when you find a trout in the milk.” — Henry David Thoreau, November 11, 1854

I could not fathom what this might mean — despite Google’s many examples of its use — until this information: During an 1849 dairyman’s strike there was suspicion of milk being watered down. [thanks T]

So, the trout, though circumstantial, is quite suggestive (however, one would suppose most circumstantial evidence is). One thing’s for sure — it’s no red herring.