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POPULAR SCIENCE REVIEW. 
When, however, we pass beyond the great and little brain and 
approach that part of the spinal column which is in immediate 
connection with them, we are introduced to new phenomena. 
The part immediately leading from the brain is called the 
medulla oblongata, and as we subject that part to the influence 
of the extreme cold we instantly interfere with, and even stop, 
respiration, so that the animal, if it be a warm-blooded animal, 
will die, as suddenly as dies the Spanish bull from the short 
sword-thrust of the skilled Torero ; but the heart still continues 
in action, and, if the breathing be sustained by artificial means, 
the heart will remain in action even though the influence of 
the cold be made to extend to the w T hole of the spinal cord. 
When only the upper surface of the cerebrum or large brain is 
superficially frozen, the power to move remains, although the 
perception and sensation are entirely destroyed. Indeed, in 
this condition there is often active movement of the body, but 
altogether without will or desire. The motion in this case is 
not motion of one particular and exaggerated type, but general, 
uncontrollable motion, such as is seen in some forms of insanity 
in man. 
I might extend these observations respecting the removal of 
force from the brain, but I see I am already trespassing on 
the pages of the Review, and I feel that I have given enough of 
experimental fact to illustrate as much as I can this time put 
down upon paper. 
Deductions. — The Force and the Matter. 
On reviewing the facts disclosed in the experiments that have 
been described, we learn that the force by which all the mani- 
festations of brain function are sustained is the force we call 
caloric, or commonly, and by -incorrect speech, heat. Two 
evidences lead to this truth : the first, that all the manifesta- 
tions are withheld when caloric is withdrawn ; and the second, 
that all the manifestations return when the caloric is restored. 
But inasmuch as with the restoration of action, there is continu- 
ance of the impressions which were made on the brain before 
any force was drawn out of it, it follows that the extant force in 
the brain at any given moment, is not the seat of the impres- 
sion, nor the cause of it, but the means by which the matter of 
the brain is held ready for the reception of the impression, and 
for the production of those manifestations which we denominate 
functions. We are bound, therefore, to infer that impressions 
are physical realities, stamped as it were on brain matter, each 
distinct and perfect when the matter on which it is set is in 
condition for motion. Everything we remember is, I doubt 
not, thus imprinted on the brain, on infinite points of brain 
