234 
ANIMAL PATHOLOGY. 
motor function of this gastric nerve, there is now, to a certain ex- 
tent, little or no dispute. The gastric juice is the solvent of the 
ingesta of the stomach ; or the fluid by the powerful action of 
which they are converted into one homogeneous mass — chyme. 
By means of the muscular coat of the stomach, that viscus is 
kept in a continual state of agitation or motion ; every part of the 
food is gradually propelled from the cardiac to the pyloric orifice 
of the stomach, and in the course of that journey is brought, and 
probably many times in its turn, to the surface, and exposed to 
the full influence of the solvent. The experiments of almost 
every physiologist differing, and often strangely differing, in many 
points unite here. These nerves having been divided, the forma- 
tion of the chyme is not altogether arrested, but it is confined to 
the surface of the mass of food, or penetrates but a very little 
way into that mass; whereas, if they were left to exert their na- 
tural influence or power, every portion would be dissolved. If 
there were not direct experiments as to the actual motion of the 
stomach, the conclusion could scarcely be avoided, that in the 
one case every portion of the food was brought into contact with 
the gastric fluid ; and that in the other portions only of an inert 
and motionless mass, on which the parieles of the stomach press- 
ed, were dissolved. The digestion of the food is not suspended, 
but it is inconveniently and fatally delayed by the division of 
the nerves. 
There is not only an oscillatory motion, by means of which the 
food is agitated, and parted, and successive portions brought into 
contact with this fluid ; but there is a peristaltic one which causes 
the food to be gradually propelled or forced on from the cardiac 
to the pyloric orifice. An inspection of the circular as well as 
the longitudinal fibres of the muscles of the stomach will give a 
clear and satisfactory idea of this. The great spinal organic nerve 
being divided, both kinds of motion cease at once; — the superfi- 
cial portion of the food alone is digested, and the whole mass 
remains in the stomach without the possibility of extrication. 
The Sensibility of the Stomach destroyed. — These, however, are 
nerves of organic sensation as well as of motion ; and it is easy 
to imagine what, in this respect, will be the consequence of their 
division. That organic sensibility by which the sphincters, 
whether cardiac or pyloric, are governed — that feeling of com- 
fort or of annoyance — that consciousness of healthy or of de- 
ranged action or impression — as really existent as the common 
sensations of pleasure or pain — being suspended, the stomach, so 
far as feeling and motion are concerned, becomes inert or dead. 
The pylorus no longer responds to the stimulus of healthy chyle, 
and permits the escape of that portion of the food which is pre- 
