NUTRITION. 119 



of the elements that compose each, and no other. They 

 take just enough of each element, neither more nor less, and 

 combine them in the due proportion of each kind, to form 

 the part which is wanted. 



260. Although the different tissues of the animal body 

 are so nearly alike in their composition, and so slight a vari- 

 ation would produce another kind of flesh, yet, in health, no 

 mistake is made. Each organ and tissue receives flesh of 

 its own kind. Muscle is not deposited in the brain, nor bone 

 in the muscle, nor tendon in the liver. In every part, the 

 blood-vessels act with such unvarying and beautiful precision, 

 and perform their work with such faithfulness to their pur- 

 pose, that they might almost seem to be endowed with a 

 special intelligence, if we were not assured that they, even 

 the minutest of them, are under the coiistant.^supervision and 

 direction of that paternal Providence, without whose notice 

 not an atom moves nor a sparrow falls to the ground. 



261. Thus all the atoms of flesh, all the parts of the ani- 

 mal body, were first in the stomach, and next in the arteries ; 

 and then they became living flesh, and acted a while, and died. 

 Then, again, all these, with the exception of the hair, the 

 nails, and the outer skin, which grow out and fall, are once 

 more taken into the vessels, and are found in the veins. 

 The blood in the arteries differs from that in the veins, in its 

 nature and its composition. In one, it is scarlet, rich, nutri- 

 tious, loaded with new particles of digested food, and is 

 therefore capable of giving life and strength to any of the 

 tissues. In the other, it is dark purple; it h:is lost its rich 

 particles, and is therefore innutritions ; it is also loaded with 

 the dead and wasted particles that have lived and died in the 

 body. If the venous blood be thrown into the arteries, and 

 circulated through the system, it not only must fail to nourish 

 and give new particles of flesh to the tissues, but, with its 

 wasted and offensive burden, it must carry disease 01 death 

 to the body. 



262. The veins are incessantly receiving additions of the 

 particles of the exhausted flesh, and would soon be so over- 



