1 28 FURTHER INQUIRY INTO THE REASONS 
obstacle to vomiting in the horse is purely mechanical, and 
principally due to the insuperable impediment offered to 
regurgitant gastric evacuation by the large and numerous 
folds into which the lining of the stomach is thrown, when- 
ever the distended viscus is compressed. The thick mus- 
cular coat w 7 as held to act as an auxiliary impediment, by 
preventing the expansion of the larger and thicker internal 
lining. 
For the purpose of brevity and clearness I have not gone 
into some of the details reported by the experimenters, par- 
ticularly as I see no reason for entering into a minute 
analysis of the steps of their inquiry, fallacious as it is in its 
spirit and foundation. Many as are the reflections sug- 
gested by the numerous controversies to which the theme 
of our inquiry has led during the last 120 years, none is 
so curious as that which inspires surprise at seeing so many 
men, habituated to observation and experiment, directly con- 
tradicting each other in the simplest matters of fact, and 
making use of arguments so partial and exclusive, as to 
be destitute even of a priori value in the explanation of vital 
phenomena, and to admit of complete refutation by compre- 
hensive observation and logical interpretation of physical 
laws and vital conditions. 
The fact that therapeutics, as applied to the horse, ex- 
clude emetics, that the great majority of experimenters 
have agreed upon the inoperativeness of emetic substances 
even when injected into that animal's veins, did not for 
an instant suggest to Ercolani and Yella that the horse is 
really very much less susceptible to the nervous impres- 
sion of emetics than the animals which vomit, and that 
whatever its physical inability to the performance of that 
act, that w r as as a rule secondary to the vital insusceptibility. 
On the contrary, so soon as they believed that they had 
finally excited in the horse efforts to vomit, under the most 
extraordinary circumstances, and by the most powerful 
means, they thus argued : the horse is susceptible of the 
nervous impression of emetics, the horse does not vomit, 
therefore the obstacle must be mechanical. How certainly 
and completely does an assumption contrary to fact lead 
to error. To state as a general proposition that the horse is 
susceptible of the nervous impression of emetics, is to enun- 
ciate an assumption contrary to fact. To argue on that 
fallacious assumption as if it w^ere a demonstrated truth, 
must lead to error. It is remarkable that it did not occur to 
the Turinese physiologists that the very fact of the cuticular 
coat at the cardiac end of the stomach being very loose and 
