118 ON ZOOLOGY. 



admire the Providence which has thus so effec- 

 tually guarded against accidents, which, in their 

 consequences, would eventually have been de- 

 structive to the whole animal kingdom. 



Upon the taste being gratified, and tiie first 

 operation completed, namely mastication, the food 

 is conveyed into the stomach, there to undergo a 

 second process, that of digestion, and afterwards a 

 third, the converting it into a milk-like fluid, 

 denominated the chyle. This fluid is then ab- 

 sorbed and conveyed through a series of almost 

 invisible glands into a tube, named the thoracic 

 duct, which ascending, finally empties its con- 

 tents into one of the large returning vessels of the 

 heart, there to be intermixed with the deteriorated 

 blood, brought from different parts of the body 

 for atmospherical purification ; thus subjecting 

 the chyle or newly formed blood to a fourth pro- 

 cess, namely, the respiratory, previously to its 

 being in a fit state to nourish the body, and to 

 supply the glands with materials for secretion. 



We here see in the preparation of those supplies 

 which in the first instance were necessary for the 

 support of animal life, nature has employed no 

 less than four important processes to effect her 

 object; and as each of the organs concerned, was 

 liable, from a variety of causes, to be so deranged 

 in its functions as to interrupt her intention; it is 

 obvious that great ingenuity was required in the 

 mechanism, and a nice adjustment of its several 



