It used to be required that PhD students (even in the sciences, and in the US) had to demonstrate written understanding of at least one foreign language. When I

It used to be required that PhD students (even in the sciences, and in the US) had to demonstrate written understanding of at least one foreign language. When I got my doctorate in microbiology in the 1990s that rule was still officially on the books, but not enforced. But certainly before WWII and even into the 1960s there was a lot of research being published in Russian, French and German besides English. Even today, China still publishes many Chinese-language journals which go mostly untranslated.