How did Jan Ingenhousz build on Joseph Priestley’s observations about plants and air?

Joseph Priestley famously demonstrated that plants could restore air that had been "damaged" by combustion, enabling it to support life and flame again. Jan Ingenhousz expanded upon these observations by identifying the specific conditions and mechanisms required for this process, which we now know as photosynthesis.12

Ingenhousz’s key contributions included:

• The Necessity of Light: By submerging plants in water and observing the release of bubbles, he discovered that plants only restore air in the presence of sunlight.12
• Localization of Activity: He determined that only the green parts of a plant are capable of performing this restoration.12
• Respiration vs. Purification: He observed that all living plant parts "damage" the air (releasing carbon dioxide) in the dark. However, he concluded that during the day, the rate of oxygen production through photosynthesis far exceeds the rate at which plants release carbon dioxide, resulting in a net purification of the air.12