Does it do what it says on the tin? It doesn’t really matter. This was the start of the Sixties. Our cultural scene was in a state of upheaval. And art wasn’t about styles or description any more. It was about breaking down constraints and exploring ideas. And Piero Manzoni was one of the wackier and more provocative pioneers. This, after all, was the Italian who flogged little inflatable balloons of his breath, who consecrated a series of thumbprinted hardboiled eggs to high culture, who rolled up lines of ink in little sealed canisters and sold them, who signed naked people and issued them with a certificate of authenticity. Manzoni was interested in purging the art scene of romantic pomposity. The art object was on a par with the supermarket commodity, he suggested. He mocked the widely accepted idea of the anointed artist who could transubstantiate dross by his merest touch. Tins of his excrement, he stipulated, should be sold by weight according to the current price of precious metal. Base matter was turned into gold.

And that’s why it doesn’t matter what is in those little yellow tins so familiar to any modern art aficionado. They are not about the innate value of a little piece of merda d’artista . They are about the conceptual breakthrough. You only have to go into Tate Modern to see how valued that has been. The galleries are full of modern-day conceptualists who pay homage to Manzoni.

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