Wilhelm Eduard Weber
In 1857, a scholarship brought him abroad to train with Wilhelm Eduard Weber (1804-1891) at Georg-August-Universität of Göttingen and Émile Verdet at the École normale supérieure in Paris. Arndtsen was appointed at the Rikshospitalet in 1860. In 1864 he was awarded the Crown Prince's gold medal ("Kronprinsens gullmedalje") for the dissertation regarding the use of electricity in medicine ("Om Electricitetens Anvendelse i Medicinen").