In hmolscience, Samuel Sommerring (1755-1830) was a German physician and anatomist noted for his early 1790s correspondences with Goethe, on chemical polarity theory, and for his 1795 work on non-anatomical structure soul theory.
In a 2 Jul 1792 letter to Sommerring, Goethe stated the following: 
"It seems to me at least for the moment, that everything connects well when you in this teaching for Barbie takes the concept of polarity to guide. Like ... it was impossible to connect the previously chemical experience with optical, you only see the first chapter of each Dyeing, even the newest of Berthollet, in which the progress of chemistry, we must admire the way so much. Because basically ... the thing itself must be very simple, as all higher, the general principles of acting. As you pointed out quite rightly, the effect of acids and friendship is to the Yellow Red and Yellow, the alkalis to the Blue Red and Blue brought in a great relationship, what offers us the countless chemistry experiments. "
“Mir scheint wenigstens für den Augenblick, daß sich alles gut verbindet, wenn man auch in dieser Lehre zum Versch den Begriff der Polarität zum Leitfaden nimmt. … Wie unmöglich war es bisher die chemischen Erfahrungen mit den optischen zu verbinden, man sehe nur die ersten Kapitel einer jeden Färbekunst, selbst der neuesten von Berthollet, in welcher wir die Fortschritte der Chemie übrigens so sehr bewundern müssen. … Denn im Grunde muß die Sache an sich sehr einfach sein, wie alle höhere, ins Allgemeine wirkende Prinzipien. Wie Sie ganz richtig bemerkten, wird die Wirkung und Freundschaft der Säuren zu dem Gelben und Gelbroten, der Alkalien zum Blauen und Blauroten in einen schönen Zusammenhang gebracht, wozu uns die Chemie unzählige Versuche anbietet.”
In 1795, Sommerring, in his On the Organ of the Soul, dedicated to German philosopher Immanuel Kant, argued that the soul is not found in the anatomical structure of the brain, e.g. in the pineal gland as Rene Descartes (1640) had surmised, but rather in the liquid of the brain, which he called acqua venticulorum cerebri, and that this was a type of animated fluid.  Sommerring requested Kant’s opinion on this work and in response Kant sent Sommerring a four page letter, the main conclusions of which are as follows: 
“We are told now by this discovery that the common sensorium is neither more nor less than the water in the chambers of the brain. There it isolates the nerves whose ends pass thither so that the sensations are not confused. It is at the same time a medium of communication between them.
A difficulty [he goes on] is that water is not organized. Without organization no matter can be thought of as providing an organ for the soul. However, if we turn from the mechanical uniformity of water to its chemical composition there is more scope. Water has now been split by pneumatic experiments into two gases [Cavendish, 1781]. Each of these gases besides its own basis has caloric. This latter may be decomposed into light and other material like light, which again is decomposable into colors … [and so on]. A drop of water, a grain of sand, or things ever more simple still, are inexhaustible in the diversity of their least parts, even to an understanding so limited as man’s.
Plants extract from water a vast quantity of matters. Who knows what the nerves might find to their hand in the water of the brain? Suppose the nerves in their several kinds can decompose the water in the brain, its elements may give rise to different sensations. The excitations over, the elements might then reunite. Thus, what this book claims might come to pass. But the seat of the soul? No.
One cannot assign a relation in space to what is determinable only in time. Many fancy they feel their thought in their head, but that is a mistake. This mistake is to infer that the cause of sensation is there where it is experienced. They attribute though to traces in the brain left by impressions of sense. The supposititious traces carry no inference as to the seat of the soul. It is just material acting as at the common sensorium, as at an antechamber of the mind. Water within the chambers of the brain might truly be a common sensorium. But the seat of the soul? No. That leads to √-2, an impossible quantity.”
1. (a) Lillyman, William J. (1982). “Analogies for Love: Goethe’s Die Wahlverwandtschaften and Plato’s Symposium” (pg. 143). Goethe’s Narrative Fiction: the Irvine Goethe Symposium. Walter de Gruyter.
(b) H.A. Briefe II, 146.
2. (a) Reill, Peter H. (2005). Vitalizing Nature in the Enlightenment (pg. 152). University of California Press.
(b) Palmquist, Stephen. (2010). Cultivating Personhood: Kant and Asian Philosophy (pg. 163). Walter de Gruyter.
3. (a) Sherrington, Charles. (1940). Man on His Nature (pg. 201). CUP Archive.
(b) Kant, Immanuel. (date). Sammtl. Werke, X, 112 (Hartenstein, 1839).
● Samuel Thomas von Sommerring – Wikipedia.