L. L. Zamenhof L. L. Zamenhof Ludwik Lejzer Zamenhof (; , ; – ), credited as L. L. Zamenhof and sometimes as the pseudonymous Dr. Esperanto, was a Polish-Jewish ophthalmologist and the creator of Esperanto, the most successful constructed language in the world. He grew up fascinated by the idea of a world without war and believed that this could happen with the help of a new international auxiliary language, which he first developed in 1873 while still in school. Zamenhof was born on 15 December (3 December OS) 1859, the son of Markus Zamenhof (27 January 1837 - 29 November 1907) and
Ludwik Hirszfeld Hirszfeld was the first to foresee the serological conflict between mother and child, which was confirmed by the discovery of the Rhesus factor. Upon this basis he developed, in the last years of his life, an "allergic" theory of miscarriage and recommended antihistamine therapy. Hirszfeld also investigated tumors and the serology of tuberculosis. His discovery of the infectious agent of paratyphoid C had far-reaching consequences for differential diagnosis. Ludwik Hirszfeld Ludwik Hirszfeld (5 August 1884 in Warsaw – 7 March 1954 in Wrocław) was a Polish microbiologist and serologist. He is considered a co-discoverer of the inheritance of ABO blood