The article describes when natural sciences first appeared in schools and how they gave a decisive push to the foundation of the Riga Polytechnic. It shows how big the influence of contacts with famous scientists was. In the 19th century scientific developments and tendencies arrived quite fast in the Baltic Provinces. Many schools and the Riga Polytechnic used the German language, so it was a natural consequence to be in a regular contact and under the steady influence of Western Europes scientific developments. The explorations and the scientific publications of natural scientists like Alexander and Wilhelm von Humboldt, Karl August von Baer, August Toepler, Karl August Möbius, Wilhelm Ostwald and others were known in the Baltic Provinces, some were personally known, of others the books were in the libraries. Scientists in Riga were not only interrested in their scientific subjects but also in the methods of teaching them. Without beeing in the main focus of interest theories and methods of didactics played an importand role.