mutual friend. Carl Warburg was received by Sir James Clark (royal physician to Queen Victoria and Prince Albert). Clark became an advocate of Warburg's Tincture. Carl Warburg was also friends with Prince Metternich, another Austrian politician and statesman, who was one of the most important diplomats of the era. In addition, Warburg had been received by Ferdinand I of Austria. Laboratory near Sutton, Surrey in 1850s During the 1850s and possibly 1860s, Carl Warburg utilised and owned purpose-built laboratory premises near modern-day Belmont, Sutton, in Downs Road. This was established in the late 1990s, by a local historian who also identified the exact location. This laboratory was situated in the vicinity of where the Sutton branch of the Royal Marsden Hospital now stands. The approximate location is shown on this map: . The reason for the laboratory being located here was related to secrecy considerations: in the mid 19th-century this area of the present London Borough of Sutton near Banstead Downs was very remote and lowly populated. This laboratory building was demolished in 1881. Publications Pamphlets and booklets 1839, London. Specific for fever, now first introduced into Europe (8 pp.) 1846, Vienna. Pharmakologische Notizen über die Wirkung und den Gebrauch der Dr. Warburg'schen vegetabilischen Fiebertinctur (title translates as 'Notes on the pharmacological effect and the use of Dr Warburg's vegetable fever tincture') (c. 24 pp). 1870, London, Warburg Tincture: statement proving by numerous official documents its remarkable curative powers in fevers... (c. 60 pp.) Countries of residence Carl Warburg was born and educated in Germany. In the 1830s Warburg lived in British Guiana (Guyana) (South America), travelling there due to "personal circumstances", where he worked as a physician and developed his Warburg's Tincture. When he introduced his tincture into Europe, in 1839, he moved to London, England. In the mid-late 1840s, Warburg lived in Vienna, Austria, where his tincture was being trialled. He left Vienna following the 1848 revolution, moving to London where he resided until his death in 1892. He lived at numerous addresses in London. Carl Warburg obtained British naturalisation in 1852. Later life Carl Warburg lived in poverty in his old age. Writing in 1870 – then aged in his 60s – he stated that he was a "poor man", "impoverished" due to the cost of having produced and donated, over the course of several decades, a total of in excess of 80,000 bottles of his tincture