First edition, first impression, of this scarce picture book by the German social scientist and graphic designer Marie Neurath, illustrating the types and behaviours of subatomic particles. Neurath (1898-1956), together with her husband Otto and their colleague Gerd Arntz, was one of the inventors of Isotype, an international visual language which made use of simplified graphics and diagrams to represent complex information to the public. Marie was "a remarkable practitioner" of the system, who "researched, calculated, and co-designed nearly every Isotype ever created, from the early days in Vienna in 1925 all the way to when she retired in 1971" (Forrest). Marie continued working on Isotypes after Otto's death in 1945, becoming best known for the series of children's books she published over the next 20 years. "In children's educational books Marie found an ideal place to put Isotype's methods into practice. Young readers were more engaged by pictures than words, and this focus on the visual meant these books were easily translated and published abroad, fulfilling Isotype's original aims of being truly international" (Inglis). Jason Forrest, "The Missing Legacy of Marie Neurath", Medium, 20 January 2020, available online; Theo Inglis, "Meet Marie Neurath", Medium, 3 October 2019. Square quarto. Original illustrated boards, spine and front cover lettered in black. Spine lightly chipped at head and discreetly reglued at foot, extremities a little rubbed, endpapers browned, contents clean. A very good copy.