his family's grief, until he was finally permitted to return home and bury his brother. Upon his return home, Pfeiffer undertook his first publication, a personal recollection of his experience entitled Erfahrungen über die Cholera, gesammelt in dem Hospital zu Warschau im Sommer 1831. Family Louis Pfeiffer was married twice. His first marriage was to Luise Philippine (née Nathusius, 2 September 1811 - 18 September 1891), daughter of the industrialist Johann Gottlob Nathusius. They were married on May 19, 1832, and divorced in 1841. This union produced three children, all of whom died young: Gottlob Wilhelm Richard Paul (13 April 1834 - 9 March 1835) Louise Marie Anna (5 January 1836 - 29 May 1840) Johanna Caroline Marie (25 October 1837 - 1 June 1840) Louis Pfeiffer married his second wife, Wilhelmine Friederike (née Wagner, 10 April 1823 - 26 June 1900), on October 9, 1842. Their marriage lasted until Pfeiffer's death, and produced six children: Wilhelm Conrad Hermann (30 September 1843 - 9 May 1883), a merchant in Spain, specializing in the trade of hazelnuts. Louis Hermann (6 December 1845 - 20 August 1887), an architect and public works supervisor in Frankfurt am Main. Richard Albert (30 November 1847 - 6 May 1906), a district judge in Rotenburg an der Fulda; married the daughter of high court judge Ludwig Moeli. Adolf Carl Gabriel (4 December 1850 - 1906), a Hauptmann in the 27th Nassau Field Artillery Regiment. Wilhelm Franz Carl (13 September 1852 - 19 January 1871) Rosalie Marianne Caroline Sophie Mathilde (22 February 1855 - 1925) Scientific Career & Later Life After his return to Cassel and his marriage, as well as the death of his eldest son, Pfeiffer had grown unhappy with his medical practice, finding the state of medical science at the time insufficient for his intellectual needs, and gave it up to focus on scientific studies and literary works, particularly in the fields of botany and conchology. His first scientific work, published in 1837, was a book cataloging and describing the various cactus species used in German gardens. It was well received, and as a result, he became known as "Kaktus-Pfeiffer." In 1839, Pfeiffer was sent to Cuba with Johannes Gundlach and Eduard Otto in order to study the flora, fauna, and natural history of the West Indies, and it was this experience that piqued his interest in mollusks, conchology, and malacology. he group explored