Quinine giving a further half dose. No injectable preparation of quinine is licensed in the US; quinidine is used instead. Quinine is a flavor component of tonic water and bitter lemon drink mixers. On the soda gun behind many bars, tonic water is designated by the letter "Q" representing quinine. According to tradition, the bitter taste of anti-malarial quinine tonic led British colonials in India to mix it with gin, thus creating the iconic gin and tonic cocktail, which is still popular today. Nowadays, the amount of quinine in tonic is much lower and drinking it against malaria is useless. Quinine
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