AND ANIMAL LIFE. 431 



oppression sometime,? experienced in the precordial 

 region. 



It is not at all essential to the argument that 

 the circulation be primarily deranged, and that 

 it subsequently react upon the respiration; it 

 is probable that the latter, in the greater number 

 of instances, is, in the first place, influenced by 

 the transmission of impressions to the mind, the 

 consequence of which is, that the circulation be- 

 comes irregular from depending exclusively on 

 the conditions of the respiratory function. 



DXXVIII. As nausea' increases, the pulse 

 becomes more rapid and small, till at length it is 

 scarcely perceptible. The pale and collapsed 

 appearance of the face, and the indications of 

 suppressed or incomplete circulation on the sur- 

 face of the body, are proofs that the blood is in- 

 ternal rather than external, in relation to its usual 

 distribution. The lungs receive more blood than 

 they are accustomed to receive ; and if the quan- 

 tity be much greater than usual, it is clear that the 

 heart will have to propel an augmented proportion, 

 but this is evidently less arterialized from the in- 

 creased quantity of blood in the chest, and there- 

 fore the stimulating principle is diminished. 

 This is the reason why the heart does not contract 

 and dilate energetically ; but the necessity of con- 

 tinuing to act still remains, and consequently the 

 blood is propelled in a small and gentle stream. 



