In this series of articles, I show you some of the exhibits contained in the Museum of Urology, hosted on the BAUS website (www.baus.org.uk) and in this one I am joined by Mary Garthwaite, retired urologist and Chair of The Urology Foundation, who was instrumental in obtaining the exhibit discussed below for the museum.
After history and examination, there follows investigation, to confirm your diagnosis, and the simplest test is urinalysis. In a previous Urology News article, I discussed the early history and development of uroscopy; we saw the ancient physicians gazing into their matulas of urine and diagnosing (or some times prophesying) their patients’ ailments (or futures!).
This time I want to bring you right into the modern world of 1911, that exciting time of discovery and science just before the First World War.
Figure 1.
Figure 2.
Figures 1 and 2 show a Soloid Urine Test Case made in Berlin, by Burrows Wellcome in the early 20th century. Burroughs Wellcome & Co. was founded in England in 1880 by the American pharmaceutical magnates Silas Burroughs (1846–1895) and Henry Wellcome (1853–1936). These pocket analysis cases, sold by Wellcome, included a drinking water analysis kit, a bacteriological test case and a blood test case, as well as this urine one. They were produced partly to advertise and sell their Soloid brand patented chemicals which they claimed were “pure, reliable and portable preparations, accurate in strength and uniform in their chemical activities”. The case was kindly donated to the BAUS Museum of Urology by Michael Geary. Time has taken its toll however and the set is no longer complete, but Figure 3 shows a complete case illustrated in a 1911 Wellcome publication.
The set included a urinometer to measure specific gravity. This is a hydrometer specifically for the measurement of urine. Made of glass, it consists of an air containing float with a weight below and a graduated scale above. When floated in a test tube of liquid, the meniscus would read 1.0 for water and between 1.010 and 1.030 for healthy urine. Too high is concentrated urine, which may be caused by dehydration, glycosuria, urinary tract infection (UTI), syndrome of inappropriate antidiuretic hormone (ADH) secretion, amongst other things. Too low, dilute urine, can be due to renal failure, diabetes insipidus, interstitial nephritis, etc. The urinometer was first introduced by William Prout (1785–1850) in 1825. A mercury weighted version was invented by Johann Florian Heller (1813–1871) in 1849.
There was also an Esbach Albuminometer in the case. Introduced in 1874, by the French physician Georges Esbach (1843–1890), it was a graduated tube to which urine was added to mark ‘U’ and a reagent of 1% picric acid and 2% citric acid was added to mark ‘R’. The tube was corked and mixed and left to stand for 24 hours. The height of the precipitate formed was read against graduations to calculate the percentage protein present.
As well as the Soloid chemicals used in the albuminometer, the set contained reagents to carry out the haemosiderin test, Fehling’s test and indigo test. The haemosiderin test includes a microscopic examination of the urine precipitate for the characteristic large blue haemosiderin granules when potassium ferrocyanide is added to the sample. Fehling’s test, introduced by Hermann von Fehling (1812–1885) in 1848, is used to detect glucose in the urine. Fehling’s solution, a mix of copper sulphate and sodium potassium tartrate, is boiled with urine. The copper sulphate is reduced by glucose forming a coloured precipitate varying from yellow to brick red, depending upon the concentration of glucose. The indigo test is another test for sugar. Diluted urine is boiled with sodium nitrophenylpropriolate, the presence of sugar produces a deep blue colour.
The set also contains a spirit lamp, to heat the urine samples, and indicator papers to test the pH. William Prout was the first to use the litmus test on urine. Normal urine pH ranges between 4.5 and 8.0. As well as abnormal urine pH signifying disease, it was important to know the pH to correctly carry out other biochemical tests.
Urine has always been the easiest bodily fluid to investigate and examine. For thousands of years healers have looked at a patient’s urine to assist in diagnosis and treatment of illness. Nicholas of Cusa (1401–1464), a German Bishop and polymath, summarised it beautifully when he wrote, “since the weight of blood or the weight of urine is different for a healthy man and for a sick man . . . wouldn’t it be especially useful to a physician to have all these differences recorded?”
The scientific analysis of urine emerged (as with all chemistry) from alchemy; the eccentric German physician Theophrastus von Hohenheim (1493–1541), better known as Paracelsus, was an early advocate of this. He described the appearance of “milk” in urine which was heated or mixed with vinegar, revealing proteinuria. If not fully understanding what he had found he realised it was related to renal disease. Johanne Baptist Van Helmont (1577–1644), a follower of Paracelsus’ ideology, 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.
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.
Figure 3.
The earliest form of dipstick testing for glucose in urine was described in 1850 by the Parisian chemist Jules Maumené (1818–1898). Maumené 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, who marketed 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 10 different reagents.
This tiny Wellcome urinalysis kit is a lovely thing and, at the time it was made, gave doctors, wherever they were, the ability to test a patient’s urine to help diagnosis and cure. With its up-to-date diagnostic biochemical tests, it brought the laboratory to the doctor ‘in the field’. But compare the measuring, mixing, diluting, heating and waiting of that with your almost instant dipstick of today.
