420 
ON INCREMENT OF ANIMAL HEAT. 
Of the Symptoms Produced by Increment of 
Animal Heat. 
When by the exposure to air of a high temperature under 
the conditions named above^ or when, f^rom any other cause, 
the temperature of the body itself is increased, a train of 
symptoms follow "which are as simple in their character as any 
in nature, and which cover whole fields of what is called 
medical experience. The first sign we observe is the accumu¬ 
lation of heat itself; the fever y I may most properly call it, in 
order to retain an old and significant name. But the fever is 
not to be considered as a mere s 3 ^mptom; it is trul}^ a symptom, 
but it carries with it, when it is properly understood, all the 
rest of the symptoms. It is primary, the others follow and 
are dependent upon the primary. 
Next to increase of heat, and the first result upon such 
increase, is increase of involuntary motion, motion of respira¬ 
tion, motion of circulation. This increase of speed in the two 
grand sets of muscles, the prime movers of the body, is as 
much a quick driving from excess of heat as is the driving of 
an engine from heat in the furnace. Thus the pulse increases 
with the increase of heat in the body, both in tension, and in 
rapidity of stroke, and it falls, wdth fall of temperature, either 
in tension or rapidity, or both. This excess of motion in 
many cases is of immediate service to the organism ; it is an 
equalising process ; it prevents to a marked extent the further 
increment of heat; it employs or uses up the force. 
When the accumulation of heat is moderate and slow, the 
increase of motion is frequently succeeded by fre^ elimination 
of water from the body ; and here again is a most effective 
equalising agency. Indeed, this process of elimination once 
started, it is very difficult to sustain or advance increment 
of animal temperature. By this equalising process of evapo¬ 
ration, we are enabled, in the Turkish bath, to resist those 
extremes of heat which I have already spoken of as endur¬ 
able. 
But when the accumulation of heat is rapid and determi¬ 
nate, instead of free elimination from the excreting and se¬ 
creting surfaces, there is the opposite condition of dryness, or, 
as is commonly said, suppressed secretion. In all acute in¬ 
flammatory conditions, we know this suppression of secretion 
to be a bad sign. What is the meaning of it ? The meaning 
is most simple, and is this. Under a given accumulation of 
heat, as near as 1 can estimate an increment of from seven to 
eight degrees, there is an act of contraction of the whole ar- 
