Ever hear the terms "fat," "protein," and "carbohydrate"? That's because of William Prout. Born in 1785, he was the first person in history to figure out the basic components of foodstuffs. A brilliant chemist, he's still best known for having one of the nearest misses in all of science. Probably he shouldn't have named the one wrong hypothesis of his career after himself.
Prout had an interest in food from the moment it was swallowed until well after it had left the body. He was the first to prepare pure urea. He discovered that the stomach juices contained hydrochloric acid. He found out that the feces of a boa constrictor contained a massive amount of uric acid, and kept a boa on hand from then on to harvest a steady supply of the acid for his studies.
You could say that Proud was fascinated by the basic components of almost everything, including all the interesting new elements that were popping up during his lifetime. After going over the results of the many scientists who had managed to find the weights of various elements, Prout noticed something very strange. All of the weights of the elements seemed to be multiples of one particular number. That number was the weight of hydrogen. Prout's Hypothesis was this - that all elements had weights that were multiples of the weight of a hydrogen atom, and therefore a hydrogen atom was the basic building block of the universe.
And that is so close to right. Although each atom is - save for the negligible mass of the electron - an approximate multiple of the weight of a hydrogen atom, the neutron ruined it for Prout. His idea was so close to right, though, that it spurred a massive scientific drive in the right direction. There was a stampede of scientists rushing out to ever-more-correctly weigh the various elements to see if Prout's Hypothesis was correct. When they found that certain elements seemed to break hydrogen's mass into fractions, they began to modify the hypothesis rather than refute it. For example, it was thought that perhaps the basic building block of the universe was a quarter of a hydrogen atom. It was only later that scientists discovered that many elements have different isotopes, the different neutrons of each skewing the measurements of large quantities of the atoms.
The hypothesis remained useful for the next hundred years, and was on Ernest Rutherford's mind when he set about separating hydrogen nuclei from the larger nuclei of other elements. Overall, Prout's idea shows how science works - one idea leading to another, each increasing in accuracy. It's nice to know that being wrong can lead to so much rightness. (I think, though, that both Prout and anyone else would have preferred being right in the first place.)
Illustration by Aleksey Klints via Shutterstock