Assertion: hemoglobin's oxygen | /r/HasProperty | prepared by the heating of red lead oxide
Facets:
value: almost simultaneously
type: TEMPORAL
Source sentences:
text: Oxygen was prepared almost simultaneously by K. Scheele (1769–70) by calcination of nitrates (KNO 3 , NaNO 3 ), manganese dioxide (MnO 2 ), and other substances and by J. Priestley (1774) by the heating of red lead oxide, Pb 3 O 4 , and mercuric oxide, HgO. D. Rutherford discovered nitrogen in 1772.