HOFFMANN, Friedrich. Observationum physico-chymicarum selectiorum libri 3. Halae, Prostat in officina libraria Rengeriana, 1722 4to. 210x170 mm. legatura coeva piena pelle bruna, fregi ai piccoli ferri in oro al dorso, risguardi marmorizzati tagli rossi a spruzzo. Pagine [28, compeso Frontespizio], 378, [22]. Frontespizio in rosso e nero con vignetta incisa. Buono stato di conservazione. Prima edizione. Duveen: “this work contains the author’s most important chemical works. Hoffmann opposed the iatrochemical wiews od Sylvius and Tachenius. He invented “Hoffman’s Anodyne” still in use in the British Pharmacopoeia. Hoffman’s experimental investigations were largely concerned with the examination of mineral waters and he did much towards perfecting the analytical methods of his time. He showed that sulphates are not the same as nitrates and that the base or calx) from alum is different from tha of chalk ; hitherto such calxes were considered identical.”