Worth its weight in gold: the history of urine

Worth its weight in gold – the history of urine
Jonathan Charles Goddard

Why on earth would urine be worth its weight in gold? It’s just wee!

Well, you could answer that in a couple of ways. Medically speaking, urine can be extremely valuable in diagnosing disease. The little pot of urine brought into the GP’s surgery or hospital clinic can help the doctor find kidney disease, liver disease, cancers and diabetes. Or, believe it or not, urine was at one time a very valuable commodity, bought and sold by merchants and artisans.

Urine in the diagnosis of disease
There is some evidence that the colour of urine was studied by the Babylonians. There is an ancient Babylonian cuneiform symbol from around 4000BC which represents haematuria, red or bloody urine. Although it is not clear how it was related to diagnosis or treatment.

In the Sanskrit medical manuscripts of ancient India differences in urine were clues to diagnosis. Wonderful descriptions were used such as, “urine the colour of turmeric” or “the colour of brandy” or urine “similar to that produced by a mad elephant”!

It wasn’t just the colour of urine which was used, the consistency, smell and even the taste could help. Interestingly more than just the appearance was used. An excess of bile caused the urine to have a bad odour and taste (yes taste!) of salt and of course the urine of a diabetic patient tasted sweet. In India it was called Madhumeha or honey urine. In the West it was called Diabetes mellitus, the name is derived from both Greek and Latin words and means siphoned or drained honey. The Hindu doctors also noticed that long trains of black ants would be attracted to the ground where the diabetic had voided the sugary urine.

In mediaeval medicine uroscopy, the study of urine, was key to diagnosis. Whole books, coloured charts and even songs were written about it. Gyles de Corbeil (1165 – 1213) wrote a “Poem on the judgement of urines” as an aide memoir for his students at Salerno to sing.

It was so important, the sign of a doctor was a urine bottle; like a stethoscope is now. These bottles were called matula. They were supposed to represent the shape of the bladder; the base was rounded so any sediment could be carefully examined. Because of this and as it was made of glass (the clearer the better) it was usually transported in a woven wicker basket.

Unfortunately, things went a bit too far, as well as helping to diagnose disease which caused clear changes in the urine, some practitioners claimed to be able to identify every disease, tell whether a woman was going to give birth to a boy or girl and even predict the future. These quacks and charlatans were called “Pisse Prophets”.

The Uroscopist by Richard Brakenburg (1650-1702), reproduced with permission of the EAU History Office

Famously, Thomas Linace (c1460 – 1524) suggested patients may as well show him their shoe as their urine to be diagnosed. Linacre was the first president of the Royal College of Physicians and passed a college statute forbidding diagnosis on urine alone.

However, as magic and alchemy slowly began to change into science uroscopy began change into urinalysis.

The eccentric German physician Theophrastus von Hohenheim (1493–1541), better known as Paracelsus, described the appearance of “Milk” in urine which was heated or mixed with vinegar, we now know this is protein and although he did not fully understanding what he had found he realised it was related to kidney disease. Johanne Baptist Van Helmont (1577-1644), a follower of Paracelsus, was the first to advocate the measuring of the specific gravity of urine by comparing the weight of the patient’s urine to a similar volume of rainwater.

1993 German postage stamp. BAUS collection.

Lorenzo Bellini (1643-1704) evaporated the urine to find the differences were due to the variations in amounts of water and solids present. Hermann Boerhaave (1668-1704) another pioneer in the measurement of urine, discovered urea. In 1772, Liverpool physician Matthew Dobson (1732–1784) evaporated the urine of diabetics obtaining a residue indistinguishable by taste and smell from ordinary sugar. William Cruickshank (d.c.1811) worked out this was a vegetable sugar rather than milk sugar. Cruickshank also noted that, in the urine of dropsy patients, addition of nitrous acid produced “white coagulum similar to that of boiled egg white”, hence first describing the nitric acid test for proteinuria. He also noted that muriatic acid could detect bile in urine by producing a green colour.

Portable urinalysis kit, Wellcome, c.1911. BAUS collection.

Portable or pocket urine testing sets were used for diagnosing away for the hospital setting. This set made by Wellcome around 1911 includes a urinometer to measure specific gravity or concentration of urine. Too high may indicate dehydration, glycosuria, UTI, syndrome of inappropriate ADH secretion, amongst other things. Too low, dilute urine, renal failure, diabetes insipidus, interstitial nephritis etc. There is also an Esbach Albuminometer to calculate the percentage protein present. There were also tests to look for sugar in the urine and a spirit lamp, to heat the urine samples, and indicator papers to test the pH or acidity.

Modern bedside or clinic urine testing is done using a dipstick, a strip of paper or plastic with small squares of chemical reagent which change colour depending on what is in the urine. These can be held up against a colour chart (not dissimilar to our mediaeval forbears) but more usually now, this is done electronically.

Urinalysis strips. Author’s image.

The earliest form of dipstick testing for glucose in urine was described in 1850 by the Parisian chemist Jules Maumené (1818–1898). Maumené’s used a strip of merino wool impregnated with tin protochloride. When a drop of urine was applied to the treated wool and heated over a candle, the strip would turn black if the urine contained glucose. In 1883, George Oliver (1841 – 1915), a GP in Harrogate, developed urine testing papers for sugar and albumin. The idea was soon commercialised by the pharmaceutical company Parke Davis marketing pocket urine analysis kits containing these papers. In 1956, husband and wife team Helen (1923–2021) and Alfred (1913–2000) Free developed the Clinistix dipstick test for glucose for Miles-Ames Labs (now Bayer Diagnostics). In 1981 they created the Multistix test holding ten different reagents.

Electronic analysis machine for urine dipstix. Author’s image.

Urine the valuable commodity

In the comic fantasy novels by the late Sir Terry Pratchett, there was a character called Harry King who empties the chamber pots of the city and sells the contents. He earns the sobriquets, Piss Harry and the King of the Golden River, but goes on to make a fortune and get a knighthood. Like all of Pratchett’s plots this is based on historical fact. Waste, including urine was valuable.

Urine was used by fullers to clean and whiten clothes, by tanners to remove hair from animal skins in the production of leather and by clothiers to fix dyes in cloth. In Roman towns and cities pots were left at street corners for urine to be collected and sold to the fullers to clean clothes and make the togas of the rich brilliant white. This business was so successful that the emperors Nero and Vespasian taxed it. This Vectigal Urinae or Urine Tax horrified Titus, Vespasian’s son who thought it degrading for his father to tax something so disgusting as smelly urine. Vespasian was said to have held a gold coin under his son’s nose and asked, “and how does that smell?”. Urine not only made money for the businessmen but for the imperial coffers too.

Urine was also sold to and used by leather workers or tanners. Finally, urine can be used to make gunpowder, or more correctly, saltpetre, one of the components of gunpowder. As you can imagine this was an important commodity, particularly if a country was at war. King Charles I issued a law where saltpetre men could collect urine or urine soaked earth (for examples from toilets, dovecots or cattle sheds) from anywhere, including private land.

Barrels of gunpowder. Image in the public domain

So, urine was once worth its weight in gold. Now, its still very useful to doctors to diagnose diseases, less so I would say for washing, tanning leather or firing your cannons!

 

This article has been partly adapted from:

Garthwaite M, Goddard JC,  A Laboratory in your pocket. Urology News, 30:  2026

Goddard JC,  Uroscopy.  Urology News, 21(6): 22-23, 2017