3IO THE HISTORY OF BIOLOGY 



Sommerring s work on the brain 

 His curious work fiber das Organ der Seele, which he dedicated to Kant, is a 

 combination of anatomical inquiry and philosophical speculation. In it he 

 gives a detailed description of the brain and its nerves, illustrated with 

 splendid engravings. His account of the origin of the nerve-stems in particu- 

 lar is admirable, considering the age in which it was written, and he has 

 rendered a still greater service to science by treating, for the first time, the 

 sympathetic nervous system as a pair of nerves independent of the central 

 nerve system, "which pair is in indirect, but not direct, connexion with the 

 brain and spinal cord." The whole of this study of the brain, however, forms 

 the basis of a highly fantastic speculation upon the brain as the organ of the 

 soul, or, to be more exact, upon the location of the "sensorium commune," 

 which in the German is translated as "das gemeinschajtliche Emffindungsort." 

 By this is meant that part of the brain in which the sense-impressions con- 

 verge and co-operate. Ideas of this kind in regard to the localization of the 

 soul in the brain had indeed long been current; Descartes adopted for this 

 purpose the glandula pinealis, Perrault the ??2edulla oblongata; Swedenborg 

 alone was guided on the right path by his brilliant intuition when he drew 

 attention to the pyramid-cells of the cerebrum. Sommerring tries to prove 

 that all the cerebral nerves open into the central cavity of the brain and that 

 in connexion therewith the cerebral fluid is the organ of consciousness; the 

 only point that worries him is: "Kann eine Fltissigkeit animirt sein?" which, 

 however, he answers in the affirmative on arguments derived from the Bible, 

 Aristotle, and modern writings. This assertion, which in our own day, when 

 protoplasm and its derivatives have so often had to serve as wholly or at 

 least partially fluid, should not be regarded as utterly absurd, nevertheless 

 aroused grave doubts in the minds of Sommerring's contemporaries, just as 

 his philosophical argumentation in general shocked the students of natural 

 science; his good friend Goethe wrote him a letter in which, with reflective 

 and observant criticism, which he unhappily did not always employ in his 

 own writings, he warns him against letting philosophical speculations inter- 

 fere in scientific investigations. And Sommerring in actual fact learnt wis- 

 dom from the opposition he met with; his later works are in the main based 

 on exact natural science; his reputation as one of the leading anatomists of 

 his age was greatly enhanced by them and has been confirmed by posterity. 

 There was one scientist, a contemporary of Sommerring's, who ap- 

 proached far more nearly to the modern conception of the structure of the 

 brain and nervous system, but through his own fault he managed to acquire 

 a somewhat doubtful reputation; this was the "phrenologist," Franz Joseph 

 Gall (1758-1818). Born at Baden, he went as a medical student to Vienna, 

 became a doctor, and carried on a medical practice there. At the same time 

 he began to interest himself in the study of the brain's structure and its 



