John Scott Haldane

In his 1917 lectures Haldane described work on breathing air very short of oxygen. The alveolar carbon dioxide pressure still regulated the breathing, but it was set at a lower level². The early panting reflected the large reserve of carbon dioxide in the blood and lymph. When oxygen fell only gradually, no evident panting appeared, though breathing still increased³. He also pointed to the kidney. Sodium chloride vanishes from the urine once its blood concentration falls below normal⁴.

Bayliss cited Douglas, Haldane and Haldane (1912) for the finding that the relative affinity of haemoglobin for oxygen and carbon monoxide differs between individuals. They placed the cause in the globin, since the haematin part is always the same. Bayliss found it hard to square this with iron alone binding the gases⁵. He also reported Hartridge's refinement of the Douglas and Haldane carbon monoxide method, using the shift of absorption bands⁶. Hartridge found no oxygen secretion by the lungs. Douglas and Haldane held that it could not be detected until acclimatisation had developed⁷.

Haldane argued that the reactions of an organism, both internal and with its environment, are co-ordinated so that its life maintains itself. He said ordinary inorganic observation shows nothing like this¹. Lillie later cited Haldane's 1908 British Association address, which called nutrition a constant process of reproduction and heredity an axiom for biology. Lillie held that these remarks did not dispose of the problem of heredity⁸.