Analysis of information sources in references of the Wikipedia article "Pyromorphite" in English language version.
On hydrosiderum [i.e., iron phosphide, Fe2P] as a calcined [i.e., roasted] iron [that is] bonded with phosphoric acid), Chemische Annalen für die Freunde der Naturlehre …, 1 (5) : 390–399. From p. 394: After remarking that lead ores that contain phosphorus can be treated with strong acids to produce phosphoric acid, Klaproth notes that: " … wie solches zuerst Hr. Gahn in Schweden entdeckt, ich selbst aber bey Unersuchung des krystallisirten grünen Bleyerzes von der heil. Dreyfaltigkeit zu Zschopau bestätigt gefunden habe." ( … as such Mr. Gahn in Sweden first discovered, I myself, however, have found [to be] confirmed by investigation of the crystallized green lead ore [i.e., pyromorphite] from the Holy Trinity at Zschopau in Germany]