Rosenheim was born in New York to banker William and his wife Maria Hallgarten.
He studied under Carl Rammelsberg, receiving a doctorate in 1888 with a dissertation on vanadium tungstic acid.
He then founded a private laboratory with Carl Friedheim, and later worked with Richard Joseph Meyer.
He was dismissed from the university and also on the urging of Heinrich Hörlein[1] from the Chemical Society in 1933 due to his Jewish origin.
His students included Otto Liebknecht, Gerhart Jander, and their main work was on heteropolymetalates.