130 FURTHER INQUIRY INTO THE REASONS 
proved, that the cardiac muscular fibres are 'permanently con- 
stricted. All analogy and physiological knowledge suggest 
as reasonable that these muscular fibres arranged in alternate 
circular, spiral, and longitudinal layers, can close or enlarge 
the aperture they surround, according to the nature of the 
stimulus they receive ; it is certain the aperture is often 
largely opened for natural purposes, and it remains to be 
determined by experience whether the opening of the cardia, 
which is one of the movements concurrent to the act of vomit- 
ing, takes place in the horse. This question must be solved 
by experience, to which M. Colin has appealed, conclusively so 
in his opinion, without result in mine ; and that because he has 
performed his experiments under such conditions, that their 
results are not applicable to the question under considera- 
tion. Thus he argued that the muscular closure of the 
cardia is the reason why the stomach cannot evacuate its 
contents through the oesophagus, from the three following 
experiments. Firstly, in a horse just fed, he cut through the 
linea alba and duodenum ; through the pylorus he introduced 
his finger into the stomach, and found that orifice partially 
open, its border at intervals gently compressing the finger. He 
then opened the stomach at the large curvature, and found 
the cardia quite closed ; on pushing his finger into the 
orifice it was forcibly constricted. In a second experiment, 
performed on a horse that had been feeding for several hours 
and had just drunk half a pail of water, the anterior flexure 
of the colon w 7 as displaced so as to lay bare the greatly dis- 
tended stomach wTich was forcibly compressed with the hands 
in various directions, without anything escaping through the 
cardia. The viscus was only partially evacuated, by its 
contents flowing slowly towards the intestine. K I repeated,” 
to translate M. Colin’s words, “ this experiment in other 
horses placed in the same conditions. In one instance, the 
compression was so powerful as to tear through the mus- 
cular coat at the right end of the great curvature. The 
results w^ere always the same. If the contents of the stomach 
were fluid, they partially passed into the duodenum ; if they 
were comparatively dry, they became clogged, and only 
passed into the gut in small proportions. The obstacle is, 
therefore, at the cardia.” I can simply regard these experi- 
ments as furthermore substantiating the very well-known 
fact, that during the early part of the process of digestion 
the cardiac is quite, and the pyloric orifice almost , closed. I 
cannot see how these results, obtained by such violent expe- 
riment during the process of healthy digestion, can in any 
way apply to solve the question of vomiting. The fact that 
