Litmus "Lecanora tartarea" (Norway, Sweden), "Variolaria dealbata", "Ochrolechia parella", "Parmotrema tinctorum", and "Parmelia". Currently, the main sources are "Roccella montagnei" (Mozambique) and "Dendrographa leucophoea" (California). The main use of litmus is to test whether a solution is acidic or basic. Wet litmus paper can also be used to test for water-soluble gases that affect acidity or alkalinity; the gas dissolves in the water and the resulting solution colors the litmus paper. For instance, ammonia gas, which is alkaline, turn the red litmus paper blue. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or
Heberly Run load is . The acidity concentration at the headwaters of Heberly Run is 4.40 milligrams per liter and the alkalinity concentration is 5.84 milligrams per liter. The daily loads of these substances are and , respectively. Downstream of Meeker Run, the acidity concentration is 2.87 milligrams per liter and the acidity load is per day. The alkalinity concentration is 6.83 milligrams per liter and the daily load is . At the mouth of Heberly Run, the acidity concentration is 2.80 milligrams per liter and the concentration of alkalinity is 6.93 milligrams per liter. The daily loads for these substances are