William Prout

William Prout was born on January 15, 1785 in Horton, in Gloucestershire, England, where his family had lived for generations.  His father was a farmer and like most rural youths his early education was almost negligible, being over by the time he reached 13.  At age 17, aware of his lack of education he pursued a path of systematic learning, first at a private academy in Sherston, where he learned the rudiments of Latin and Greek, then at Redland Academy, a seminary in Bristol, where he paid his tuition by teaching the younger students.  He spent two years at Redland during which his interest in chemistry was excited and which remained with him throughout his life.  With the intention of a career in medicine, in 1808, at the age of 23, he began at the University of Edinburgh (Oxford or Cambridge were out of the question due to Prout's low social status).  He graduated with his M.D. in 1811.

After graduation Prout went to London and took rooms off of Leicester Square.  In order to gain experience in medical practice he walked the wards of the United Hospitals of St. Thomas' and Guy's.  He was licensed by the Royal College of Physicians in 1812 and set up a practice.  Each day he would rise early so that he could conduct chemical research before he breakfasted at 7, and then saw patients during the day.  Prout was not primarily a clinician and was lax in charging his patients, but he spared no expense in devising apparatus for his chemical experiments, which was why he was not as financially successful as many of his medical colleagues.  Prout was part of the medical revolution of the early 19th century, understanding the causes of disease, rather than just the symptoms.

Prout's chemical research made many breakthroughs in the understanding of the importance of chemistry in human physiology. In 1817 Prout isolated purified urea (the nitrogenous waste product in urine) and described its reactions.  In 1823 he showed that hydrochloric acid is the acidic component of gastric juice.  In 1827 he proposed a classification of food substances, including sugars and starches, oily bodies, and albumins, which today we classify as carbohydrates, fats and proteins.  Prout's belief in the importance of chemistry in physiology put him at odds with the vitalists, who believed that chemistry did not play an important role in physiology, and this disagreement played out in the medical journals of the day.

Despite his his many advances in the science of physiology Prout's most famous discovery was in physical chemistry and not physiological chemistry.  In 1815, observing the tables of elemental atomic weights that were available, he anonymously hypothesized that atomic weights of the elements were multiples of the atomic weight of hydrogen and that the hydrogen atom was a fundamental particle (which he called the protyle) of which  the other elements were built.  While we know now that atomic weights used today are not exact multiples of the weight of hydrogen (due to the mass converted into binding energy holding nuclei together and the averaging of isotopic weights), Prout's insight was so important that in 1920 Ernest Rutherford chose to name the newly discovered proton, giving credit to Prout.

Honors won by Prout include election into the Royal Society in 1819 and the Copely Medal, the oldest and most prestigious award given by the Royal Society, in 1827.  As Prout aged he became increasingly hard of hearing, eventually going totally deaf.  It was this deafness that caused Prout to drop out of scientific circles and discontinue his researches.

Prout died on April 9, 1850.


References:

Brock, W.H.; "The Life and Work of William Prout"; Medical History(1965)9:101-126

Rosenfeld, Louis; "William Prout: Early 19th Century Physician-Chemist"; Clinical Chemistry(2003)49:699-705

William Prout Wikipedia Entry