In his paper "Observations on Respiration and the Use of the Blood", Priestley was the first to suggest a connection between blood and air, although he did so using phlogiston theory.
Dalam makalahnya "Observations on Respiration and the Use of the Blood", Priestley menjadi yang pertama menyarankan suatu hubungan antara darah dan udara, walau ia melakukannya menggunakan teori flogiston.