Magnus published 84 papers in research journals. His research output was continuous over his lifetime: the first memoir was published in 1825 when he was still a student, and the last appeared shortly after his death in 1870. From 1825 to 1833 he was occupied mainly with chemical researches. These resulted in the discovery of the first of the platino - ammonium class of compounds (see Magnus's green salt). He was first to identify the three sulfonic acids sulphovinic acid, ethionic acid and isethionic acid and their salts; and, in cooperation with CF Ammermüller, of per-iodic acid and its salts. He also reported on the diminution in density produced in garnet and vesuvianite by melting (1831). Subjects on which he published research after 1833 include: the absorption of gases in blood (1837–1845); the expansion of gases by heat (1841–1844); the vapour pressures of water and various solutions (1844–1854); thermoelectricity (1851); electrolysis of metallic salts in solution (1857); electromagnetic induction of currents (1858–1861); absorption and conduction of heat in gases (1860s); polarization of heat (1866–1868); and the deflection of projectiles from firearms (see Magnus effect). From 1861 onwards he devoted much attention to the question of diathermancy in gases and vapours, especially to the behaviour in this respect of dry and moist air, and to the thermal effects produced by the condensation of moisture on solid surfaces. Magnus was an experimenter, not a theoretician.