422 
ON INCREMENT OF ANIMAL HEAT. 
rapidity that the fatal increment is reached directly, we have 
an extension of contraction from the involuntary to the 
voluntary muscles, and therewith general convulsions, which 
will soon become tetanic in character. At last there is a 
general rigidity of the muscles and death from permanent 
spasm of the muscles of respiration and of the heart. 
To complete the history of the symptoms brought on by 
increment of heat within the body, there are, as the fatal in¬ 
crement of heat is approached, evidences that change is taking 
place in the nervous centres, for the animal becomes comatose. 
There is little difficulty in explaining the cause of the coma; 
it is due to the contraction of the vessels which supply the 
brain with blood, and to the subsequent changes in nervous 
matter incident to withdrawal of blood. To use a common 
expression, the brain and nervous centres die; to use a more 
accurate expression, their parts sink into molecular rest or 
inertia. 
Such is induced inflammatory fever. We are meeting with 
the identity of it in every day of practice on the human sub¬ 
ject. We never see a case of acute inflammatory disease, but 
w^e see the increment of heat. What vve have to feel in all 
its fulness and to appreciate in all its breadth is the grand 
truth that every symptom, primary or secondary, is dependent 
on the accumulation of the force we call heat; and, that the 
whole of the phenomena we observe, up to death itself, are 
due simply and solely to the inability of the body, from some 
accident or other, to dispose of that active force which the 
body in perfect health sets free for the mere purpose and 
intent of ministering to the production of thos^ processes 
which are summed up in the term life. 
Phenomena after Death from Increment 
OF Heat. 
Rigidity .—Animals which have died from increment of 
their organic heat soon become rigid, the rigidity being 
strongly pronounced. This is in strict accord with the many 
previous facts I have noted respecting the influence of heat 
in bringing on rigor mortis. The rigidity extends generally 
—wherever, in fact, there is muscular fibre—and it is so 
determinate in the arterial system that if immediately after 
death a tube be placed in the aorta, and water be injected, 
the extremest force, short of a force that will rupture the 
vessels, fails to push the fluid round the circulation. The 
rigidity remains also a long time. 
Temperature .—At and immediately after death, the tempe- 
