ANt) ANIMAL LIFE* 153 



existence of such a state of the vessels, we should 

 be necessitated to grant that vegetables have also 

 their spasms, for I have shown them to exhibit 

 the same general laws of organization, and to be 

 affected by the same general causes as the animal 

 economy. But instead of entertaining for a 

 moment such an idea* let the philosophical mind 

 examine the evident operations of physical agents, 

 and it will find that the assumption of this is 

 equally as gratuitous as the vis medicatrix of the 

 same author. 



CLX VIII. The external application of cold, and 

 certain states of internal disease, determine the 

 blood upon the internal viscera, and thereby deprive 

 the capillary vessels of their usual fulness ; but the 

 constriction which succeeds is not the cause of in- 

 ternal congestion or of fever > but is the simple effect 

 of a depressing power, and in no stage of the 

 disease is it to be regarded in the light of a cause. 

 CLXIX. We have, as yet, considered only 

 the influence of a moderate degree of cold, and 

 the principles by which the system conforms to 

 these changes ; but we must now examine the 

 influence of an extreme degree, and endeavour to 

 explain the concomitant phenomena* When an 

 individual is exposed to intense cold, certain un- 

 pleasant sensations arise, such as pain or coldness 

 of the extremities, and oppression of the chest ; 

 Difficulty of breathing, insensibility of the feet* 



