24 On Respiration and Animal Heat. 
It is somewhat remarkable, that this sup- 
posed amendment of Crawford’s theory should 
have been so generally adopted. The authors 
of it evidently did not understand the prin- 
ciples they were attempting to refute; their 
objections to them may be applied with equal 
force against their own principles; they ob- 
tain the very same end by means much less 
probable : yet the physiological writers of this 
country have almost universally embraced their 
innovation upon the original system. I can- 
not ascribe this to any other cause than that 
unwarrantable neglect of cultivating the doc- 
trine which instructs us respecting the capa- 
cities of various hodies for heat. Having 
now given my own views of the present 
state of the theory of Respiration and Animal 
Heat, I shall proceed to make a few observa- 
tions upon the facts and experience relative 
to this subject, since the time of Crawford. 
~ Davy, Henderson and Pfaff have almost 
established the fact, that a small portion of 
azotic gas disappears by respiration; this es- 
caped the notice of Lavoisier and Crawford, 
who seemed to have concluded, that oxygen- 
ous gas was the only part of the atmosphere 
changed by breathing. Whatever other use 
may be-attached to the fixation of azote in 
