Quinine side effects include deafness, low blood platelets, and an irregular heartbeat. Use can make one more prone to sunburn. While it is unclear if use during pregnancy causes harm to the baby, use to treat malaria during pregnancy is still recommended. Quinine is an alkaloid, a naturally occurring chemical compound. How it works as a medicine is not entirely clear. Quinine was first isolated in 1820 from the bark of a cinchona tree. Bark extracts have been used to treat malaria since at least 1632. It is on the World Health Organization's List of Essential Medicines, the most effective and
Cinchona Garden in January 1861. James Taylor, the pioneer of tea planting in Sri Lanka, was one of the pioneers of cinchona cultivation. By 1883, about were in cultivation in Sri Lanka, with exports reaching a peak of 15 million pounds in 1886. The cultivation (initially of "Cinchona succirubra" and later of "C. calisaya") was extended through the work of George King and others into the hilly terrain of Darjeeling District of Bengal. Cinchona factories were established at Naduvattam in the Nilgiris and at Mungpoo, Darjeeling, West Bengal. Quinologists were appointed to oversee the extraction of alkaloids with John Broughton in