The primary difficulty is that the addition of small amounts of silver nitrate to urine results in the formation of colloidal silver halides. Craig and Jackson 1 overcame this by the addition of ...

Nitrite is generated from urinary nitrate reducing active of bacteria while leukocyte oxidase reflects the presence of white cells in the urine. If both of these are positive then UTI is present ...

and then reacted with potassium in wood ash to form potassium nitrate. Because nitrogen is also found in the urea in human urine, in the Satsuma Domain in what is now Kagoshima Prefecture ...