Nils Wallerius

Nils Wallerius (Stora Mellosa 1 January 1706 – Funbo 16 August 1764) was a Swedish physicist, philosopher and theologian. He was one of the first scientists to study and document the characteristics of evaporation through modern science methods and also one of the first and most important followers of Christian Wolff in Sweden.

Nils Wallerius was born as the son of provost Erik Nilsson Wallerius of Stora Mellosa and his spouse Elisabeth Tranaea. He was a brother of chemist and mineralogist Johan Gottschalk Wallerius. He studied philosophy and physics at the University of Uppsala, where he in 1746 became professor of logic and metaphysics. In 1755, he received a professorship in theology established by bishop Andreas Kalsenius. His praised studies in physics specially in the field of evaporation earned him a place as the 26th member of the Royal Swedish Academy of Sciences in 1739. Wallerius research was mostly focused on if and how evaporation occur in open or vacuumed environments. His experiments with evaporation in different environments ranged from observing the weight loss of an egg over an entire year or how long a cup of wine from the Rhine region evaporated, to large scale sealed copper tanks filled with various fluids observed over time. His results, showing that evaporation also do occur in sealed environments still stands today and is an important factor in various areas, mainly industries.

Wallerius was also a religious man that, while influenced of the enlightened time he was living in, viewed many of his younger colleagues liberal beliefs as a threat to religion. After a conflict with his senior mentor Samuel Klingenstierna he left the physic faculty and instead became a professor in theology. During the 1750s he made a name of himself in the theological debate as a known devoted defender of his Wolffian beliefs. He spoke at least 5 languages fluently (Swedish, Latin, English, German, French) and had special permission to buy foreign literature deemed blasphemous by the Swedish church in order to study it. Wallerius actively participated in over 200 disputations both of his own works and by others where he often rhetorically attacked those who showed a too much enlightened view on science and theology. When Emanuel Swedenborg was asked after the death of Nils in 1764 what he thought the professor was doing in heaven he replied "He still goes about and holds disputations".

Wallerius was also an avid and popular lecturer that during periods of his career spent 8–10 hours per day lecturing for a huge number of students. His lectures became so popular that he sometimes placed them at 2:am in the morning to hold the number of listeners at acceptable levels. During his life he published many works in his various fields of studies among them are his 750 pages handbook to physics "Elementa physices" and his 870 pages study of the soul through the philosophies of Christian Wolffin "Psychologia Empirica, ea continens quae de Anima humana Indubia Experientiae fide cognoscuntur, Methodo Scientifica Pertractata" (1755) .

Nils Wallerius was married twice. His first spouse, the daughter of a rich merchant Catharina Ubstrom, he married in 1739 and she died in 1751. In 1757, he married Anna Margaretha Boy. One daughter of his first marriage, Catharina Magdalena Walleria was married to his successor, the theology professor and principal at the University of Uppsala Erik Kinmark.