Was it found by Rutherford and Chadwick that oxygen and carbon cannot be transmuted by bombarding them with alpha particles???
I searched internet and got this one.
Russell was able to demonstrate the transmutation of gases in the Bloomfield, New Jersey research laboratory at the Westinghouse Lamp Company on Sept. 30, 1927. Transmutation of hydrogen and oxygen to nitro- gen, and, nitrogen to oxygen and hydrogen was accomplished.