AND ANIMAL LIFE. 379 



mouth from 97 to 77, by introducing small 

 pieces of ice, and allowing them to melt there ; 

 and he says that the effect would have been 

 much greater, if the hand, instead of the mouth, 

 had been thus circumstanced. The mouth, from 

 its vicinity to the heart, and from the great quan- 

 tity of blood which it receives, is cooled with 

 comparative difficulty, and it speedily regains its 

 ordinary temperature from the same cause ; but 

 the hand, from conditions precisely opposite to 

 these, is greatly and quickly affected by the 

 same means. 



CCCCLL After surgical operations, or inju- 

 ries of the body, the separated surfaces very 

 frequently unite by what is called the first in- 

 tention. This desirable object is sometimes ren- 

 dered tardy, or impossible, by an impoverished 

 state of the system, or by the gloomy passions of 

 the mind. It is facilitated by whatever excites 

 agreeable feelings, or tends to invigorate the 

 powers of the system. I have already endea- 

 voured to prove, in various parts of this work, 

 that the blood, during the influence of depress- 

 ing passions, is deficient in its usual qualities, 

 because the sanguineous fluid, by the exercise of 

 such mental states, is brought to the lungs in great- 

 er quantity than natural, perverting the conditions 

 indispensable to oxygenate completely the blood, as 

 stated in the first chapter. 



