History of malaria and brain which are the most constant post-mortem indications of chronic malaria infection. He related the prevalence of malaria in swampy areas to the presence of flies and recommended swamp drainage to prevent it. In the nineteenth century, the first drugs were developed to treat malaria and parasites were first identified as its source. French chemist Pierre Joseph Pelletier and French pharmacist Joseph Bienaimé Caventou separated in 1820 the alkaloids cinchonine and quinine from powdered fever tree bark, allowing for the creation of standardized doses of the active ingredients. Prior to 1820, the bark was simply dried, ground to a
Tonic (music) Tonic (music) In music, the tonic is the first scale degree of a diatonic scale (the first note of a scale) and the tonal center or final resolution tone that is commonly used in the final cadence in tonal (musical key-based) classical music, popular music and traditional music. The triad formed on the tonic note, the tonic chord, is thus the most significant chord in these styles of music. More generally, the tonic is the pitch upon which all other pitches of a piece are hierarchically referenced. Scales are named after their tonics, thus the tonic of the scale of