In January 1961 when Nonie changed her mind and would not agree to a divorce, I asked Maria, who had quite sufficient money at this time, if she would return to Paris, and I left for Port Elizabeth where I stayed at the Beach Hotel. Maria sold most of the furniture from the Johannesburg flat and put the three Chinese carpets into storage, and then followed me to Port Elizabeth where she soon made a number of women friends. She asked a lawyer, Marcus Jacobs, if he could further the divorce proceedings. I had no enthusiasm about this because I could see that the situation was causing great distress to Nonie and the children. Since Maria would not return to Paris, I decided to fly to Australia to undertake a study on the epidemiology of lung cancer similar to that which I had already undertaken in South Africa and which the Tobacco Research Council wanted to see repeated in Australia. Because I was adamant about going to Australia, and since I did not invite Maria to come with me, she flew back to Paris.

I arrived in Melbourne and hired a car and drove to Canberra, the capital. There I went to see Mr S.R. Carver, the Commonwealth statistician, and Mr V. Pickering, the principal of the Australian demography department and other officers in the Commonwealth Bureau of Census and Statistics. I asked them if they would collaborate with me on a study of lung cancer mortality in Australia. I also had the assistance of Sir Edward Ford, the professor of preventative medicine, and of Professor Oliver Lancaster, the professor of mathematical statistics, at Sydney University. We studied all deaths from lung cancer in Australia over a ten-year period and found, when the deaths were analysed by birthplace and age-group, that immigrants from Britain to Australia had a higher mortality from lung cancer than the Australian-born, but a lower mortality than those who had remained in Britain.