900 
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 vayi. 
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- 
sd process, has been incontrovertibly proved 
y 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 xf after the operation of dividing both 
vagi.t In an experiment made by Sédillot on 
a dog the digestion must at least have been par- 
tially restored, as the auimal lived two months 
and a half.{ Sédillot 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 
Haller,|| Brunn,§’ De Blainville,** Dumas,t++ 
Dupuy,f{ 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 
oan a l’Histoire de la Digestion, p. 133-4. Paris, 
t Versuche tiber die Regeneration der Nerven. 
hundert und zehnter versuch., S. 99. 1787. 
: eo Thése au Nerf Pneumogastric, &c. Paris, 
: aks Essa i sur la Physiologie de l’Estomac. Paris, 
Opera Minora, tom. i., p. 359-60. Expert. 
hsb : 
4 De Ligaturis Nervorum. Ludwig Scrip. Nerv. 
Min. Sel., tom. ii., p. 286-7. Expt. 2, 3, and 6. 
** Propositions extraites d’un Essai sur la Ke- 
spiration. Paris, 1 
tt Journal Général de Médecine, tom. xxxii, 
tt Journal de Médecine, Chirurgie, &c., tom. 
XXXVii. 
Sur le Principe de la Vie, p. 214. 
it Dissertatio Experimenta quedam de Ciborum 
Concoctione complectens. Edinburgh, 1818. 
4 Inquiry into the vital Functions. 
*** Quarterly Journal of Science, &c., vol. xi., 
p. 40. 
PAR VAGUM. 
pre ome 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. a 
Effects of lesion of the i 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 experimen 
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,t Dr. Holland,t 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 thoracie — 
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 wi 
loss of substance. Arnold, in his experiments 
upon hens and pigeons, ascertained that the 
fluid secreted from the stomach was acid, thut 
it was not perceptibly diminished in ntity, 
and that it was capable of converting ( 
into chyme.||.  Longet, in his experiments 1 pe 
quadrupeds, found that the fluid secreted fro 
the stomach coagulated milk and reddent 
turnsol paper. He further states, that the quai 
tity of gastric juice secreted appeared to him t 
be greater than in the sound animal. 
great number of experiments, more especial 
if the animal survive the operation a short ti 
only, the secretion of gastric juice is tem 
rarily suspended, and this enables us to expla 
the frequent occurrence of negative results 
such researches. ; 
Effects of lesion of the vagi upon the 
cretion of mucus from the inner surface of 
stomach and intestines—Sir B. Brodie reli 
from experiments in which animals were ] 
soned by arsenic where the usual watery ¢ 
* Elements of Physiology, translated by Ba 
vol. i., p. 597, 2nd edit. e. 
t Opus cit. tom. ii. p. 483. : 
cae An Experimental Inquiry, &c, chap. x. Edit 
§ Opus cit. 
||. Opus cit. p. 142. 
Opus cit, tom. ii. p. 382. 
