Microcosmic salt (see infobox for other names) is a salt found in

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

with the formula Na(NH₄)HPO₄. It is left behind in the residues after extracting the urea from dried urine crystals with alcohol. In the mineral form, microcosmic salt is called stercorite. The first extraction of pure

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

came from this salt, when Hennig Brandt attempted to extract

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile ...

from urine. Microcosmic salt is used in the laboratory as an essential ingredient of the microcosmic salt bead test for identification of metallic radicals on the basis of the color they produce in oxidising or reducing flame, in hot or cold condition. Microcosmic salts form a tetrahydrate.

References

Sodium compounds Ammonium compounds Phosphates {{inorganic-compound-stub