106 THE LAWS OF ORGANIC 



changes will lessen the distribution of blood upon 

 the surface of the body, because the internal ne- 

 cessities are great, and therefore we shall have, 

 from this time till the destruction of [organic ex- 

 istence, a state of circulation which may be 

 designated, in contra-distinction to the former, 

 internal. 



CI. At this period of life, approaching to 

 its acme, the respiration has become slow, the 

 contractions of the heart less frequent by almost 

 one half, the animal temperature on the whole 

 less, and the appearance of the body is at variance 

 with those indications which the infantile frame 

 exhibited. We have now the thoughtful, pale, 

 or sallow countenance : if not constitutionally in- 

 corporated, it occurs too frequently not to be 

 remarked, and it is accompanied by too many 

 internal derangements not to be felt, or traced to 

 its appropriate source. But we have not only 

 derangements, but diseases that demonstrate more 

 clearly the correctness of the division of circula- 

 tion at these different states of life, into external 

 and internal. But, before we treat of these, we 

 may advert to the exercise of the mental facul- 

 ties, and the influence which they possess in con- 

 trolling the sanguiferous system. 



CII. The sports, pursuits, or feelings of the 

 child, may be regarded as a general class of exci- 

 tants : they are either attended by muscular ex- 

 ertion, which is favourable to the oxygenation of 



