VIEWS OF CULLEN. 1051 



to the opinion of nearly all the most enlightened 

 physicians from Hippocrates down to Sydenham, 

 that fever depends on a vitiated state of the fluids, 

 it was further maintained by Cullen, that it often 

 arises from cold, the depressing emotions, and 

 mechanical injuries, without the introduction of 

 any morbific matter into the blood ; consequently, 

 that it is not owing to changes in the state of the 

 fluids, but depends chiefly on some cause acting 

 on the nervous system, or primary moving powers 

 of the animal economy, and thus producing a 

 spasmodic state of the extreme vessels. But I 

 have shewn that whatever tends to diminish the 

 functions by which the blood is formed and de- 

 purated, must very soon derange its healthy 

 properties, whether it be cold, the depressing 

 passions, concussion of the brain, an impoverished 

 diet, or impure air. 



That all the varieties of fever are modifications 

 of the same disease, and arise from different degrees 

 in the intensity or duration of the causes which 

 produce them, has been already suggested in a pre- 

 ceding chapter of this volume;* and will further 

 appear from the following general facts : 



* I have shewn that diseases of the respiratory organs predomi- 

 nate in the higher latitudes, especially during the colder months ; 

 but that the various forms of fever, cholera, dysentery, diarrhsea, 

 and hepatitis, prevail to the greatest extent in hot climates and 

 seasons, owing to the operation of a high temperature and a 

 vitiated state of the atmosphere, both of which diminish the 

 supply of heat by respiration. Ijt is therefore evident, that the 

 first class is owing to a loss, and the second to a deficient supply 





