40 OF HEALTH AND HUMAN NATURE. 



organic functions are independent of mind, and give us simply 

 the notion of life : they are digestion, circulation, respiration, 

 exhalation, absorption, secretion, nutrition, calorification. The 

 heart is their central organ. 



The organs of the animal functions are double and corres- 

 pondent, there being on each side of the median line of the 

 body, either two distinct organs, as the eyes, ears, extremities ; 

 or two correspondent halves, as is the case with the brain, spi- 

 nal marrow, nose, tongue, &c. 



The organs of the vital or organic functions, are in very few 

 instances double or situated with their centres in the median 

 line and possessed of symmetrical halves ; witness the heart, 

 stomach, liver. There are indeed two kidneys, but they con- 

 tinually differ in size, figure, and situation : the two lungs are 

 very dissimilar. 



Hence Bichat infers, that in the animal functions a harmony 

 of action in each organ or each half of the organ, is indispen- 

 sable to perfection, when both organs or sides act together ; 

 and that if such harmony do not occur, it would be better for 

 one organ or one half to act alone. This is unquestionably true 

 of the eye, but can be supposed by analogy only with regard to 

 the brain, ears, &c. It certainly does not hold good in the 

 actions of the voluntary muscles, nor in the operations of the 

 brain or spinal marrow in willing those actions. From the du- 

 plicity of the organs it also happens that one side may cease to 

 act without detriment to the function of the other ; while in the 

 vital or organic class no harmony of action is possible and the 

 derangement of any one part of an organ generally affects the 

 whole of it, an obstruction in the colon disturbs the functions 

 of all the alimentary canal. 



The animal functions experience periodical intermissions 

 sleep. The organic or vital continue incessantly, suffering merely 

 remissions : the blood constantly circulates, the perspiratory 

 fluid is constantly secreted, the stomach has no sooner digested 

 one meal than we commit another to it ; yet we shall hereafter 



