10 Deadly Things People Used To Think Were Harmless
7. Alum Bread
In 17th century England, people were big into potassium aluminium sulphate, or Alum, and who could blame them? Look at that stuff. Surprisingly, one of its major uses was as a food additive that made bread look lovely and white, which was something of a novelty at the time.
Unfortunately, though, it took them far too long to realise that it also happened to kill children by causing chronic diarrhoea, which is quite the price to pay for nice golden toast.
Nowadays we use it in fire extinguishers and to remove the moisture from taxidermised animals so, you know, probably not something that we should have ever been adding to baked goods. Just a thought.