THE HISTORICAL DEVELOPMENT OF NEUROPHYSIOLOGY 



13 



FIG. 8. Swammerdam's experiments including the one by which he proved that muscles were not 

 swollen by an influx of nervous fluid when they contracted. Fig. V is of an experiment to show the 

 change in shape of a muscle when stimulated by pinching its nerve. Fig. VI illustrates the pulling 

 together of the pins holding the tendons when the muscle contracts. Fig. VIII is the crucial one in 

 which a drop of water is imprisoned in the narrow tube projecting from the vessel enclosing the 

 muscle. Swammerdam found that when he stimulated the nerve by pulling it down by a wire, the 

 muscle contracted but the drop of water did not move. He concluded that the volume of the muscle 

 did not expand on contraction. It is the fact that the wire was made of silver (filium argenteum) 

 and the loop of copper (filium aeneum) that has credited Swammerdam with the use of bimetallic 

 electricity as a stimulus to nerve. Some authors however interpret the action in this experiment as 

 the mechanical pull on the nerve. Some originals of Swammerdam's plates can be seen at the 

 National Museum of the History of Science in Leiden. (From Biblia .Naturae. Amsterdam, 1 738). 



case his concept of intrinsic irritability differed from 

 that of GHsson in being part of a dynamic scheme in 

 which inovements of muscles and nerves acted me- 

 chanically on each other (61). Glisson (62) had been 

 among the few scientists of the seventeenth century to 

 test experimentally the Galenist doctrine that muscu- 

 lar contraction was due to an inflow of nervous fluid 

 inflating the muscle. He had demonstrated by immer- 

 sion of a inan's arm in water that the level did not 

 rise on contraction. Swammerdam,'" in Holland, 

 reached the same conclusion from experiments on 

 frogs (fig. 8). From such experiments, Glisson had 

 gone on to develop a concept of intrinsic irritability 

 varying in kind for the different nervous functions. 

 As Regius Professor of Physic at Cambridge, Glisson 



61. DE GoRTER, J. Exercilaliones Medico Qiiinta V: De aclione 

 viventium particulari. Amsterdam, 1 748. 



62. Glisson, Francis (1597^1677). Traciatus de venlricuto el 

 inleslinis. London: Henry Brome, 1677. 



was to a certain extent bound by the statutes goxern- 

 ing these professorships to teach the doctrines of 

 Hippocrates and of Galen, and this may have limited 

 him in the development of this new idea of irrita- 

 bility. 



In Haller's hands the idea blossomed into a concept 

 that was to dominate physiology for over a century. 

 His theory differed from Glisson's in that he omitted 

 the intermediate element of psychic perception be- 

 tween the irritation and the contraction. The first 

 expression of his theory of the relationship of con- 

 tractility to irritability is found in 1 739 in his com- 

 mentaries on Boerhaave's lectures and a fuller de- 

 velopment in his Elementa Physiologiae, but it is in his 



"No known portrait of Swammerdam exists. In the nine- 

 teenth century a publisher took one of the heads from Rem- 

 brandt's Anatomy Lesson and put out a lithograph w'nich he 

 labelled with Swammerdam's name. This was a stroke of 

 imagination rather than fact. 



