When Linnaeus returned to Sweden on 28 June 1738, he went to
Falun, where he entered into an engagement to
Sara Elisabeth Moræa. Three months later, he moved to Stockholm to find employment as a physician, and thus to make it possible to support a family. Once again, Linnaeus found a patron; he became acquainted with
Count Carl Gustav Tessin, who helped him get work as a physician at the Admiralty. During this time in Stockholm, Linnaeus helped found the
Royal Swedish Academy of Science; he became the first
Praeses of the academy by drawing of lots. Because his finances had improved and were now sufficient to support a family, he received permission to marry his fiancée, Sara Elisabeth Moræa. Their wedding was held 26 June 1739. Seventeen months later, Sara gave birth to their first son,
Carl. Two years later, a daughter,
Elisabeth Christina, was born, and the subsequent year Sara gave birth to Sara Magdalena, who died when 15 days old. Sara and Linnaeus would later have four other children: Lovisa, Sara Christina, Johannes and Sophia. In May 1741, Linnaeus was appointed Professor of Medicine at Uppsala University, first with responsibility for medicine-related matters. Soon, he changed place with the other Professor of Medicine, Nils Rosén, and thus was responsible for the Botanical Garden (which he would thoroughly reconstruct and expand), botany and
natural history, instead. In October that same year, his wife and nine-month-old son followed him to live in Uppsala.
Öland and Gotland Ten days after he was appointed professor, he undertook an expedition to the island provinces of
Öland and
Gotland with six students from the university to look for plants useful in medicine. They stayed on Öland until 21 June, then sailed to
Visby in Gotland. Linnaeus and the students stayed on Gotland for about a month, and then returned to Uppsala. During this expedition, they found 100 previously unrecorded plants. The observations from the expedition were later published in
Öländska och Gothländska Resa, written in Swedish. Like
Flora Lapponica, it contained both zoological and botanical observations, as well as observations concerning the culture in Öland and Gotland. During the summer of 1745, Linnaeus published two more books:
Flora Suecica and
Fauna Suecica.
Flora Suecica was a strictly botanical book, while
Fauna Suecica was
zoological.
Anders Celsius had created the temperature scale
named after him in 1742. Celsius's scale was originally inverted compared to the way it is used today, with water boiling at 0 °C and freezing at 100 °C. Linnaeus inverted the scale to its present usage in 1745.
Västergötland In the summer of 1746, Linnaeus was once again commissioned by the Government to carry out an expedition, this time to the Swedish province of
Västergötland. He set out from Uppsala on 12 June and returned on 11 August. On the expedition his primary companion was Erik Gustaf Lidbeck, a student who had accompanied him on his previous journey. Linnaeus described his findings from the expedition in the book
Wästgöta-Resa, published the next year. After he returned from the journey, the Government decided Linnaeus should take on another expedition to the southernmost province
Scania. This journey was postponed, as Linnaeus felt too busy. The same year he was elected member of the
Academy of Sciences in Berlin.
Scania In the spring of 1749, Linnaeus could finally journey to
Scania (Skåne), again commissioned by the government. With him he brought his student Olof Söderberg. On the way to Scania, he made his last visit to his brothers and sisters in Stenbrohult since his father had died the previous year. The expedition was similar to the previous journeys in most aspects, but this time he was also ordered to find the best place to grow
walnut and
Swedish whitebeam trees; these trees were used by the army to make rifles. While there, they visited the
Ramlösa mineral spa, where he remarked on the quality of its ferruginous water. The journey was successful, and Linnaeus's observations were published the next year in
Skånska Resa ("Scanian Journey"). The book comprises 561 pages and is a diary with detailed descriptions of everything he discovered in Scania. He praises the people of Scania for their hospitality, which "in no land, though everywhere I have been received well, can be compared."
Rector of Uppsala University in Uppsala In 1750, Linnaeus became rector of Uppsala University, starting a period where natural sciences were esteemed. His lectures were normally very popular and were often held in the Botanical Garden. He tried to teach the students to think for themselves and not trust anybody, not even him. Even more popular than the lectures were the botanical excursions made every Saturday during summer, where Linnaeus and his students explored the flora and fauna in the vicinity of Uppsala.
Philosophia Botanica Linnaeus published
Philosophia Botanica in 1751. The book contained a complete survey of the taxonomy system he had been using in his earlier works. It also contained information of how to keep a journal on travels and how to maintain a botanical garden.
Nutrix Noverca During Linnaeus's time it was normal for upper class women to have
wet nurses for their babies. Linnaeus joined an ongoing campaign to end this practice in Sweden and promote breast-feeding by mothers. In 1752 Linnaeus published a thesis along with Frederick Lindberg, a physician student, based on their experiences. In the tradition of the period, this dissertation was essentially an idea of the presiding reviewer (
prases) expounded upon by the student. Linnaeus's dissertation was translated into French by
J. E. Gilibert in 1770 as . Linnaeus suggested that children might absorb the personality of their wet nurse through the milk. He admired the child care practices of the Lapps and pointed out how healthy their babies were compared to those of Europeans who employed wet nurses. He compared the behaviour of wild animals and pointed out how none of them denied their newborns their breastmilk.
Species Plantarum Linnaeus published
Species Plantarum, the work which is now internationally accepted as the starting point of modern
botanical nomenclature, in 1753. The first volume was issued on 24 May, the second volume followed on 16 August of the same year. The book contained 1,200 pages and was published in two volumes; it described over 7,300 species. The same year the king dubbed him knight of the
Order of the Polar Star, the first civilian in Sweden to become a knight in this order. He was then seldom seen not wearing the order's insignia.
Ennoblement Linnaeus felt Uppsala was too noisy and unhealthy, so he bought two farms in 1758: Hammarby and Sävja. The next year, he bought a neighbouring farm, Edeby. He spent the summers with his family at Hammarby; initially it only had a small one-storey house, but in 1762 a new, larger main building was added. In Hammarby, Linnaeus made a garden where he could grow plants that could not be grown in the Botanical Garden in Uppsala. He began constructing a museum on a hill behind Hammarby in 1766, where he moved his library and collection of plants. A fire that destroyed about one third of Uppsala and had threatened his residence there necessitated the move. Since the initial release of
Systema Naturae in 1735, the book had been expanded and reprinted several times; the
tenth edition was released in 1758. This edition established itself as the starting point for
zoological nomenclature, the equivalent of
Species Plantarum. The Swedish King Adolf Frederick granted Linnaeus
nobility in 1757, but he was not
ennobled until 1761. With his ennoblement, he took the name Carl von Linné (Latinised as ), 'Linné' being a shortened and
gallicised version of 'Linnæus', and the German
nobiliary particle '
von' signifying his ennoblement. Linnaeus inscribed this personal motto in books that were given to him by friends. After his ennoblement, Linnaeus continued teaching and writing. In total, he presided at 186 PhD ceremonies, with many of the dissertations written by himself. His reputation had spread over the world, and he corresponded with many different people. For example,
Catherine II of Russia sent him seeds from her country. He also corresponded with
Giovanni Antonio Scopoli, "the Linnaeus of the Austrian Empire", who was a doctor and a botanist in
Idrija,
Duchy of Carniola (nowadays
Slovenia). Scopoli communicated all of his research, findings, and descriptions (for example of the
olm and the
dormouse, two little animals hitherto unknown to Linnaeus). Linnaeus greatly respected Scopoli and showed great interest in his work. He named a solanaceous genus,
Scopolia, the source of
scopolamine, after him, but because of the great distance between them, they never met. ==Final years==