PROCESS OF CALORIFICATION IN ANIMAL BODIES. 171 
THE PROCESS OE CALORIFICATION IN ANIMAL BODIES. 
AT THE MEDICAL SOCIETY OF LONDON. 
Mr. Richardson then read a paper on the above subject. 
He entered at great length and with considerable ability 
into the various theories which had been held to account for 
the causes of animal temperature* but did not bring forward 
any new facts. 
Dr. LanJcester was fully satisfied at the correctness of 
the chemical theory, and would be indisposed to admit the 
influence of the nervous force over purely physical actions. 
Sir B. Brodie’s experiments had no value, except as showing 
that the nervous power was necessary to the integrity of the 
system. Dr. Playfair had given much support to the che- 
mical theory in his affirmation, that a proportion exists be- 
tween the size of the lung, the amount of animal heat, and 
the degree of muscular power, as shown in the case of birds, 
in which, with unusual muscular pow T er, there is the most 
extended respiratory apparatus, and a temperature as high as 
110° to 116°. He then intimated that hydrogen plays no 
unimportant part in the production of animal heat, since in 
fats found in all kinds of fish and flesh there is an excess of 
9 equivalents of hydrogen over the 1 equivalent of that gas, 
which unites with the 1 equivalent of oxygen to form water ; 
and it is well known that fats do support combustion in the 
lungs. In reference to the action of the skin when the hody 
is exposed to great heat, he had no doubt whatever that free 
perspiration is intended to eliminate the rapidly-formed effete 
matter ; and that when from any cause, as that of excess of 
vapour in the air, this function cannot freely proceed, some 
other organ must take on the eliminating process, or disease 
will ensue. The influence of a cold is of the latter character. 
Dr. Winn believed that the production of heat mainly 
depended upon the chemical action referred to ; but affirmed 
that certain conditions occur, for which that theory does not 
account. For instance, in pneumonia, the function cannot 
be so perfectly maintained as in a state of health, and yet the 
temperature is very elevated. He had shown, many years 
ago, that this increased temperature is probably owing to 
elasticity of the arteries, and had proved by experiment, that 
if an ox 5 s artery be repeatedly elongated, the thermometer 
will rise 1° or 2°. 
Dr. Crisp informed Dr. Winn, that the elasticity of arteries 
in reptiles is equal to that of hot-blooded animals. The 
