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APPENDIX. 

Practical Observations. 
Agues.—I shall not stop to inquire here how 
far the practice of Medicine and Surgery should 
be guided by Physiology, but shall content 
myself with showing in what circumstances a 
few obstinate disorders may be advantageously 
combated, on the physiological principles which 
have been propounded in these pages. The 
stretching and coldness of the extremities, and 
the contraction of the extreme vessels which 
usher in a paroxysm of Intermittent Fever, 
were ascribed by Cullen to debility, or weakened 
action of the Nervous System; and the re-action 
of the hot stage he considered to be caused by 
the Vital Force, which is indirectly raised by the 
operation of the cold stage. This theory of 
Fever, which in part belongs to Hoffman, Cullen 
supported with a mass of circumstantial evidence ; 
