1 Different names, different cultures
Toilet is a thing that is called by numerous names around different cultures. For instance, the toilet is called 'loo' which is the British term, whereas the American title of the toilet is termed as 'out house.
2 The mystery behind a toilet being called a John
Noticed the toilet is called a John. The primary reason this term derived was because of Sir John Harrington, who contributed immensely to the toilet invention.
3 More about Sir John Harrington
Harrington was born on 4th August 1591, who was well versed in art, literary author, and courier. He is also known for his writing skills and poetry. One of the most recognized works of Harrington includes a political allegory named 'Discourse of a Stale Subject: The Metamorphosis of Ajax.'
4 The invention of the flush toilet
He was the first person to devise a flush toilet. We cannot precisely say he was the first to invent, but we can say he was the first person ever in this world to use flush toilets in Britain. We can say this because the truth that he invented such a useful thing did not come out when he was alive. In honor of devising such an incredible thing, the toilets are still called a John. (See A list of incredible scientific discoveries)
5 The precursor of the modern invention
One thing is sure that with the innovative and breathtaking invention of Sir John Harrington's flush toilet has undoubtedly proven to be a forerunner of modern invention, we all now enjoy. Although, many other people also contributed significantly to the development of the flush toilet, including J.G. Jennings, Thomas Twyford, Elvis Sloan, and some others. (See Why do some people spend a lot of time in the bathroom?)