Take a quantity of Urine (not less than 50 or 60 full buckets); let it infuse in a large oak wood barrel, until it rots and grows worms, which it will do in 14 or 15 days ”. Thus begins one of the recipes for phosphorus, written by the English scientist Robert Hooke in 1726 and inspired by the work of Henning Brand. This German alchemist dedicated his entire life to searching for proof of the divine connection between gold and the golden liquid that our kidneys distill. It is not clear how much urine Brand accumulated over the years, but his work was the first scientific effort that led to the discovery of a new element: phosphorus . Despite the minimal grammatical distance, Brand never real powdered urine managed to bridge the chemical gap between gold and rust, and died at the end of the seventeenth century ignorant of the riches that were hidden among his ammonia vats. Precisely, that distinctive bouquet of urine, ammonia, is one of the first treasures discovered by humans. Before we were able to synthesize different chemicals, urine was a rapid and abundant source of urea that, stored for a long time, turns into ammonia, essential for tanning animal skins and preserving the white of clothing ... or Spanish teeth. At least, this is reflected in a poem that the Roman Cayo Valerio Catulo dedicated to a certain Egnatius: “Now you are Celtiberian, and in the country of Celtiberia what every man loves to use to brush his teeth (…). That your teeth are so polished just shows that you are more full of pee. " Obviously, Egnatius was not one of Catullus' favorites, and so he undermined his smile with poetic dynamite ... and real too. Gunpowder requires coal, sulfides - easy to obtain elements - and also saltpeter (potassium nitrate). But this only began to be synthesized in the 20th century. Previously, those who wanted to arm themselves with explosives followed old recipes, such as those in the manual Instructions for making saltpeter , by the doctor and geologist Joseph LeConte, from 1862. There you can read: “It is necessary to stock up on a large quantity of rotten compost that must be moistened constantly with urine. The mixture will be stirred every week, and when the nitrate appears superficially by evaporation, no more urine is needed ”. Fortunately, scientists today are turning to our natural "chardonnay" for less strange , yet just as surprising, purposes. Experts from the In Vitro Fertility Clinic at William Beaumont Hospital in Michigan use derivatives of urine to treat infertility . Taking advantage of the fact that the pituitary gland secretes hormones that stimulate the gonads, scientists use these hormones to induce ovulation in women who do not produce eggs naturally. At the Chinese Academy of Sciences, a team led by Duanqing Pei has found a way to extract human cells from urine and reprogram them as neurons with the intention of fighting neurodegenerative diseases. But urine can also be used to lessen the effects of contamination. In Spain, Manuel Jiménez Aguilar, from the Institute for Agricultural and Fisheries Research and Training of the Junta de Andalucía, proposes using it to absorb CO2. In a work published in the Journal of Hazardous Materials, Jiménez Aguilar points out that: "For each molecule of urea in urine, an amount of ammonium bicarbonate is produced and an equal amount of ammonia that could be used to capture an identical portion of atmospheric CO2." To achieve this, the urine must be mixed with alpechín (centrifuged olive paste). The liquid obtained could be introduced into the chimneys of factories and houses, and into the combustion systems of cars to filter the carbon dioxide. According to Jiménez Aguilar, "CO2 emissions could be reduced by up to 1%". But the biggest urination riot is starring David Wishart . This scientist from the University of Alberta, in Canada, has written the "encyclopedia of pee". Over the course of 7 years he has reviewed all the related literature and performed hundreds of tests to discover more than 3,000 chemical compounds in urine. "It's an incredibly complex biofluid," says Wishart. "We had no idea that there would be so many components in what we flushed down the toilet." Compared to other fluids, such as saliva and cerebrospinal fluid, urine contains 5 to 10 times more compounds and greater chemical diversity. "Considering there are 356 classes of chemicals in the human body," Wishart adds, "the diversity of urine is amazing." So much so that his team found 480 compounds that had never been identified in the blood , thus breaking with the idea that the chemicals found in pee are subject to those in blood.