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his experimental investigations independently, and had an important share 

 in the discovery of the influence of the sympathetic nerve on the contrac- 

 tility of the hlood-vessels of the head ; and he first demonstrated, hy 

 positive experiment, the relation of the cilio-spinal region of the spinal 

 cord to the nerves governing these vessels. 



In the ' Comptes Rendus' for 1851 Dr. Waller gave an account of a 

 New Anatomical Method of investigating the nervous system. When a 

 nerve is cut across, the distal portion undergoes disorganization ; its fibres 

 hecome entirely altered in their microscopic characters, and may thus he 

 distinguished from those of uninjured nerves. Dr. Waller took advan- 

 tage of this effect of section as a means of tracing and discriminating the 

 fibres of a given nerve when mixed with fibres of other nerves in their 

 peripheral distribution. Moreover he showed that this method might be 

 used to elucidate the functions of nerves ; for the disorganization of nerve- 

 fibres consequent on their section involves the loss of their functional pro- 

 perties, and accordingly, when a nerve contains fibres from two or more 

 sources, its function may be analyzed, as it were, by the separate section 

 and disorganization of its different tributaries, and the consequent elimina- 

 tion of the special operation of each from the general effect. 



The introduction of this method must he regarded as one of the most 

 valuable contributions of recent times to the advancement of our knowledge 

 of the nervous system ; and it was not only happily applied by himself in 

 several neurological investigations, but it has been eagerly and successfully 

 taken up by others, who gladly acknowledged its authorship, and have re- 

 cognized it as the " Wallerian method." In the course of these researches 

 Dr. Waller also discovered that the nervous ganglia exert a certain in- 

 fluence in maintaining the integrity of nerve-fibres which are connected 

 with them. In recognition of his merit in devising and applying this new 

 method of investigation, the French Academy of Sciences conferred on him 

 the Monthyon Prize for the year 1856, and the President and Council 

 of the Royal Society awarded him one of the Royal Medals for 1860. 



From Bonn Dr. Waller went to Paris to continue his labours ; hut he there 

 contracted a low form of fever with severe cerebral symptoms : this was in 

 1856 ; and he was so much prostrated by the effects of this illness, that he 

 was for a long time quite incapacitated for work. He accordingly re- 

 turned to England, and passed the succeeding two years in comparative 

 repose ; but, his health having improved, he accepted the appointment of 

 Professor of Physiology in Queen's College, Birmingham, and the place of 

 Physician to the Hospital, and again resumed his scientific investigations. 

 These appointments, however, he did not long retain. Threatenings of the 

 heart-affection which eventually proved fatal to him, induced him again 

 to seek for quiet, and, after two years' longer stay in England, he retired to 

 Bruges, and afterwards to the Pays de Vaud. With renewed promise of 

 health and activity, he in 1868 took up his abode in Geneva with the pur- 

 pose of practising there as a physician. In the cultivated scientific circles 



