Technological and industrial history of 20th-century Canada Blood tests would become increasingly sophisticated in the coming years. The electroencephalograph, used for the diagnosis of neurological disorders was introduced in major Canadian medical institutions in the late forties. The techniques for the mass production and distribution of vaccines and for the mass public inoculation were introduced during these years. Polio was a disease that affected large numbers of Canadian children during the first part of the 20th century. In the US, research by Dr. Jonas Salk in the late 1940s led to the discovery of vaccine for the prevention of this disease. However, there was no technique for
Jonas Salk of my first year of medical school, I received an opportunity to spend a year in research and teaching in biochemistry, which I did. And at the end of that year, I was told that I could, if I wished, switch and get a Ph.D. in biochemistry, but my preference was to stay with medicine. And, I believe that this is all linked to my original ambition, or desire, which was to be of some help to humankind, so to speak, in a larger sense than just on a one-to-one basis." Concerning his last year of medical school Salk says: