Nicolas Hemmen, who was born on 24 February 1855, was a pioneering figure in the field of education in Luxembourg. After being appointed as a school teacher in Mondercange right after graduating the École Normale, he was summoned to Luxembourg City in 1885 to organise and supervise teaching at the Institut des sourds-muets (Institute for the Deaf Mute), which was founded in 1880. Upon his retirement in 1923, he was awarded the title of Teacher Emeritus of this school.
Hemmen was renowned for the lectures he delivered in Luxembourg and abroad on physical education, and on teaching people with visual impairments and speech impediments. He was one of the first people to promote the idea that physical exercise is essential to our well-being, which he did through his work, books, lectures and other publications. His numerous published studies include: Die Sprachgebrechen und deren Heiling unter der besonderen Berücksichtigung der sprachhygienischen Aufgabe der Schule (1896), Die Behandlung des blinden Kindes in dem elterlichen Hause und in der Volksschule (1896), Vorurteile und Hindernisse welche der Entwicklung unseres Schulturnen entgegenstehen (1895), Zur Fürsorge für die Idioten: Vortraggehilfen in den Lehrerkonferenzen (1897), Freiübungen für Schul-und Turnverine (1920).
A precursor to Émile Jaques-Dalcroze (1865–1950) – the creator of Dalcroze eurythmics – Hemmen combined rhythmic gymnastics with music, with the idea of using one to develop the other. He composed a series of songs for this purpose. As the gymnastics teacher at the École Normale, he introduced novice school teachers to the new methods he designed. Hemmen was a founding member of the Art à l'École (Art in School) association, and for 12 years sat on its Committee. In 1914, he became an instructor at the Cercle d'Escrime (Fencing Circle) and helped organise the Concours international de gymnastique, de tir et de sports athlétiques (International Gymnastics, Shooting and Athletic Sports Competition) in Luxembourg. In 1919, he contributed to the fund-raising drive to present Marshal Foch with a sword of honour. In 1920, Hemmen was elected vice-president of the Federation of Gymnasts. Nicolas Hemmen died on 29 July 1924 at his home on Avenue du Bois. A funeral procession led by J. Keiffer, the head school inspector in Luxembourg, and politician Hubert Clement, travelled to Notre-Dame Cemetery for a civil ceremony, without flowers or wreaths, in accordance with the deceased's wishes. The French government honoured him with the title of Officer of the Order of Academic Palms.