> back when "milk" that wasn't half chalk still might have a fish in it (see famous Thoreau quote on evidence.) This also famously happened with bread. You can

> back when "milk" that wasn't half chalk still might have a fish in it (see famous Thoreau quote on evidence.) This also famously happened with bread. You can read about it for example in Bill Bryson's "At Home: A Short History of Private Life" https://www.goodreads.com/quotes/712524-because-bread-was-so-important-the-laws-governing-its-purity https://www.goodreads.com/quotes/712524-because-bread-was-so... “Because bread was so important, the laws governing its purity were strict and the punishment severe. A baker who cheated his customers could be fined £10 per loaf sold, or made to do a month's hard labor in prison. For a time, transportation to Australia was seriously considered for malfeasant bakers. This was a matter of real concern for bakers because every loaf of bread loses weight in baking through evaporation, so it is easy to blunder accidentally. For that reason, bakers sometimes provided a little extra- the famous baker's dozen.” ― Bill Bryson, At Home: A Short History of Private Life