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
Hard water the effects of hard water on the surfactants. For this reason, water softening is often unnecessary. Where softening is practised, it is often recommended to soften only the water sent to domestic hot water systems so as to prevent or delay inefficiencies and damage due to scale formation in water heaters. A common method for water softening involves the use of ion exchange resins, which replace ions like Ca by twice the number of monocations such as sodium or potassium ions. Washing soda (sodium carbonate - NaCO) is easily obtained and has long been used as a water softener for