“The Professor elicited from the coy Reggie that in his childhood he had been in the habit of seeing abstract things in a concrete form. For Reggie the different days of the week had each a special shape, and each of the Ten Commandments a special colour. Monday was a square and Saturday an oval, and Sunday a circle with a segment bitten out.; The Third Commandment was dark blue, and the Tenth a pale green with spots. Reggie had thought of Sin as a substance like black salt, and the Soul as something in the shape of a kidney bean.”
- John Buchan, “The Gap in the Curtain”
As well as an allusion to the Pythagorean belief that beans have souls, this is possibly a relatively early literary description of synaethesia – though Galton had discussed it in the 19th Century I wonder how many fictional portrayals of it there were?