Abstract

When Vulpian submitted his medical thesis in 1853, it was already currently accepted that sensory pathways in the peripheral nervous system were distinct from motor pathways. But it was unclear whether such a distinction in the function necessarily implied specific properties. Between 1855-1860 Vulpian, together with his colleague Philipeaux, addressed the question whether it was possible in a nervous chain to replace the elements of one type with those of the another without losing normal functioning. Their first set of experiments — suturing the hypoglossus (motor) and lingual (sensitive) nerves in the dog — argued for identical properties for both kinds of nerves. A few years later, Vulpian returned to the subject to confirm his previous findings, which had not been entirely accepted. This time, taking into account the anastomosis of the chorda tympani with the lingual nerve, he had to refute his earlier conclusions and implicitly acknowledge the failure of his efforts to rationalize the nervous system. Alfred Vulpian may seem conservative in his experimental methods when compared for example to a Dubois-Reymond, however, by refusing galvanism and showing great prudence in interpreting bio-electric phenomena, he showed himself to be astonishingly farsighted in his postulation that 'molecular changes' might play a fundamental role in the activity of nerve fibres