Johann Heller and the nitric acid ring test.
Kyle
R A
RA
Shampo
M A
MA
D001317:Austria; D002624:Chemistry, Clinical / Q000266:history; D003604:Czechoslovakia; D049672:History, 19th Century; D009566:Nitrates / Q000266:history; D017942:Nitric Acid; D010678:Philately; D011507:Proteinuria / Q000175:diagnosis / Q000266:history
D009566:Nitrates; D017942:Nitric Acid