The Role of Urine in Medicine
Many physicians in history have resorted to the inspection and examination of the urine of their patients. Hermogenes wrote about the color and other attributes of urine as indicators of certain diseases. Abdul Malik Ibn Habib of Andalusia d.862 CE, mentions numerous reports of urine examination throughout the Umayyad empire. Diabetes mellitus got its name because the urine is plentiful and sweet. The use of urine therapy as a medical treatment or daily health regimen is uncommon; however, Aztec physicians used urine to clean external wounds to prevent infection, and administered it as a drink to relieve stomach and intestinal problems. The medicinal properties of urine were used in China as a part of holistic medicine, and in India, especially as part of the traditional Indian medicine, Ayurveda. The ancient Romans used urine as a bleaching agent for cleaning clothes and teeth. In Scotland, it was used to wash wool to prevent shrinking. The word “urine” was first used in the 14th century, and is a direct borrowing of the French word descended from the Latin urina and the Greek ouron, all meaning “urine,” both traceable to the postulated Indo-European root word awer, “wet, or to flow.” In Latin there is a curious twist in that whereas urina means “urine” the verb urinare means “to dive,” and to the Romans a urinator was a diver. Galen thought that urine was excreted directly from the vena cava and that the composition of urine was an indication of the nature of blood at any given time. Consequently, meticulous examination of the urine, or uroscopy, as it was then called, since ancient times, has been a strong point in diagnosis. Every medieval physician worthy of the name, carried a small flask in which to collect, and then contemplate, his patient’s urine. In the 14th century, ring worm was treated by washing the scalp with a boy’s urine. Gentile da Foligno an influential professor and teacher of medicine at the Universities of Bologna, Padua, Siena and Perugia in the first part of the 14th century, was one of the first physicians to perform human dissection.. He made a commentary on Carmina de urinarum iudiciis (Songs of urinary judgements) and to De pulsibus (About pulses) composed by Egidius Corbaliensis. This work is more than a commentary: it is a text attempting to conceptualize the physiology of urine formation. According to his writing, urine associated to the blood passes ‘per poros euritides’ (through the porous tubules) of the kidney and is then delivered to the bladder. Commenting and explaining the writing on De pulsibus, he stressed the importance of heart disease on modulating the color and output of urine and the relationship between fast pulse rate and urine output. For the originality of his thought and for the conceptualization of the relationship between pulse rate and urine characteristic, Gentile da Foligno could be considered as the first cardionephrologist. The yellow color of urine was previously thought to come from gold. Alchemists spent much time trying to extract gold from urine, and this effort led to discoveries such as white phosphorus, which was discovered by the German alchemist Hennig Brand in 1669 when he was distilling fermented urine. In 1773 the French chemist Hilaire Rouelle discovered the organic compound urea by boiling urine dry. During World War I, the Germans experimented with numerous poisonous gases for use during war. After the first German chlorine gas attacks, Allied troops were supplied with masks of cotton pads that had been soaked in urine. It was believed that the ammonia in the pad neutralized the chlorine. These pads were held over the face until the soldiers could escape from the poisonous fumes, although it is now known that chlorine gas reacts with urine to produce toxic fumes. Urine has also been historically used as an antiseptic in times of war, and when other antiseptics were unavailable, urine, the darker the better, was utilized on open wounds as an antibacterial agent.