Condition: very good. Wageningen, Veenman, 1934. Sewn. Publisher's original printed paper covers. 104 pp. Thesis. University of Utrecht. With bibliography, graphs, b/w photographs. Deals with the effects of intensity and wavelenght of light on the electric phenomena of the eye. Text in Dutch with summaries in English and German. A few library marks on title verso, ticket on cover. Condition : very good copy. Keywords : ,