Whole and not part used in combustion. The Chemical Revolution 4. Lavoisier and oxygen. New gas not air or CO2. First called 'eminently respirable air' The revolution.
Combustion is always and only to do with oxygen.
Weight gained or lost always equal to weight of oxygen gained or lost. Cannot be to do with phlogiston, as this is required to have negative, positive and no weight in various situations. The gas is the heat carrier, not the fuel. Chemists have made phlogiston a vague principle, which is not strictly defined and which consequently fits all the explanations demanded of it. It explains at once causticity and non-causticity, transparency and opacity, colour and the absence of colours.