Carl Linnaeus 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 ', written in Swedish. Like ', 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: ' and '. ' was a strictly botanical book, while ' was zoological. Anders Celsius had created the temperature scale named after him in 1742. Celsius' scale was inverted compared to today, the boiling point at
Negative temperature energy states than in the lower ones. The system can then be characterised as having a negative temperature. A substance with a negative temperature is not colder than absolute zero, but rather it is hotter than infinite temperature. As Kittel and Kroemer (p. 462) put it, "The temperature scale from cold to hot runs: The corresponding inverse temperature scale, for the quantity "β" = 1/"kT" (where "k" is Boltzmann's constant), runs continuously from low energy to high as +∞, … , 0, …, −∞. Because it avoids the abrupt jump from +∞ to −∞, β is considered more natural than