900 



PAR VAGUM. 



upon the matter that this sensation is more de- 

 pendent upon the physical condition of the 

 stomach than that of hunger. At the same 

 time we must confess that we have ourselves 

 obtained no very satisfactory evidence from 

 experiment, that this sensation is annihilated 

 by division of the vagi. 



Effects of lesion of the vagi upon the 

 function of digestion. That section or liga- 

 ture of the vagi is generally followed by 

 vomiting, in those animals susceptible of it, 

 by loathing of food and arrestment of the di- 

 gestive process, lias been incontrovertibly proved 

 by numerous experimenters. That perfect di- 

 gestion may occasionally take place after 

 division of the vagi in the neck even when the 

 cut ends are kept considerably apart, is now, 

 we are fully convinced, sufficiently established. 

 Leuret and Lassaigne have detailed an experi- 

 ment where the process of digestion went on in 

 a horse after division of the vagi with loss of 

 substance.* In one of Arnemann's experiments 

 on dogs, the digestive process must have been 

 re-established, as the animal was killed on the 

 165th day after the operation of dividing both 

 vagi.f In an experiment made by Sedillot on 

 a dog the digestion must at least have been par- 

 tially restored, as the animal lived two months 

 and a half J Sedillot also mentions that Begin 

 kept a dog alive for a month after the division of 

 both vagi. M. Chaumet further states that no 

 obvious change was observed in the digestion in 

 this dog; and he also mentions that in some 

 similar experiments made by himself a dog 

 lived fourteen days and digested. In four out 

 of seventeen dogs experimented on, we obtained 

 sufficient evidence of the restoration of the 

 digestive process. In these animals we had 

 not only removed a portion of the vagi, but 

 also of the recurrent nerves. Many experi- 

 menters, among whom we may enumerate 

 IIaller,|| Brunn,H De Blainville,** Dumas,tf 

 Dupuy,|| Legallois, Macdonald,|||| Wil- 

 son Philip,^ and Dr. Hastings,*** have never 

 obtained evidence of the continuance of the 

 digestion after lesion of the vagi, but such 

 negative experiments cannot be considered 

 as neutralizing the results of the positive 



* Recherches Physiologiques et Chemiques pour 

 servir a FHistoire de la Digestion, p. 133-4. Paris, 

 1825. 



t Versuche iiber die Regeneration der Nerven. 

 hundert und zehnter versuch., S. 99. 1787. 



t These au Nerf Pneumogaslric, &c. Paris, 

 1829. 



Essai sur la Physiologic de FEstomac. Paris, 

 1828. 



|| Opera Minora, torn, i., p. 359-60. Expert. 

 132-5-6. 



^| De Ligaturis Nervorum. Ludwig; Scrip. Nerv. 

 Min. Sel., torn, ii., p. 286-7. Expt. 2, 3, and 6. 



** Propositions extraites d'un Essai sur la Re- 

 spiration. Paris, 1808. 



ft Journal General de Mt'decine, torn, xxxii. 



|t Journal de Medecine, Chirurgie, &c., torn, 

 xxxvii. 



$4 Sur le Principe de la Vie, p. 214. 



(||| Dissertatio Experimenta qu*dam de Ciborum 

 Concoctione complectens. Edinburgh, 1818. 



H^f Inquiry into the vital Functions. 



*** Quarterly Journal of Science, &c., vol. xi., 

 p. 40. 



experiments we have mentioned above : they 

 only show what every physiologist who has 

 experimented much on this subject must be 

 obliged to confess, that the digestive process is 

 generally arrested after section of the vagi 

 during the short time the animal usually lives 

 after these nerves have been tied or divided, but 

 they can never overthrow the results derived 

 from positive experiments, provided that these 

 have been accurately performed and are free 

 from all sources of fallacy. 



Effects of lesion of the vagi upon the 

 secretion of gastric juice. We have already 

 detailed facts sufficient to prove that the re- 

 moval of a portion of both vagi does not always 

 arrest the digestion of food, and consequently 

 does not necessarily prevent the secretion of 

 the gastric juice. Mayer found the chyme acid 

 in rabbits after section of the vagi. Dieckhof 

 and Miiller state that in all their experiments 

 performed upon geese the fluid secreted from 

 the surface of the stomach after section of the 

 vagi was always acid, but was less in quantity 

 than in the sound animal.* Breschet, Milne 

 Edwards, and Vavasseur,f Dr. Holland,! and 

 Brachet, maintain that in their experiments the 

 gastric juice was secreted, since the food in the 

 stomach was more or less altered. In two ex- 

 periments we ascertained that the half digested 

 food vomited, though taken into the stomach 

 some days after division of the vagi, perma- 

 nently reddened litmus-paper; and we consider 

 the presence of chyle in the lacteals and thoracic 

 duct as observed in the experiment of Leuret 

 and Lassaigne, and in three of our own experi- 

 ments, as furnishing decisive evidence of the 

 secretion of gastric juice. In one of our expe- 

 riments the animal was rapidly recovering flesh 

 and strength when he was killed three weeks 

 after division of the vagi and recurrents with 

 loss of substance. Arnold, in his experiments 

 upon hens and pigeons, ascertained that the 

 fluid secreted from the stomach was acid, that 

 it was not perceptibly diminished in quantity, 

 and that it was capable of converting the food 

 into chyme. ||. Longet, in his experiments upon 

 quadrupeds, found that the fluid secreted from 

 the stomach coagulated milk and reddened 

 turnsol paper. He further states, that the quan- 

 tity of gastric juice secreted appeared to him to 

 be greater than in the sound animal. 5f In a 

 great number of experiments, more especially 

 if the animal survive the operation a short time 

 only, the secretion of gastric juice is tempo- 

 rarily suspended, and this enables us to explain 

 the frequent occurrence of negative results in 

 such researches. 



Effects of lesion of the vagi upon the se- 

 cretion of mucus J'rom the inner surface of the 

 stomach and intestines. Sir B. Brodie relates 

 from experiments in which animals were poi- 

 soned by arsenic where the usual watery and 



* Elements of Physiology, translated by Baly, 

 vol. i.,p. 597, 2nd ed'it. 



f Opus cit. torn. ii. p. 483. 



j An Experimental Inquiry, &c. chap. x. Edin. 

 1829. 



Opus cit. 



j| Opus cit. p. 142. 



^f Opus cit. torn. ii. p. 332. 



