12 THE PRESENT CONDITION 



jaws are working as a mill — and a very complex mill 

 too — grinding the corn, or crushing the grass to a 

 pulp. As soon as that operation has taken place, 

 the food is passed down to the stomach, and there it is 

 mixed with the chemical fluid called the gastric juice, 

 a substance which has the peculiar property of making 

 soluble and dissolving out the nutritious matter in the 

 grass, and leaving behind those parts which are not 

 nutritious • so that you have, first, the mill, then a sort 

 of chemical digester; and then the food, thus par- 

 tially dissolved, is carried back by the muscular con- 

 tractions of the intestines into the hinder parts of the 

 body, while the soluble portions are taken up into 

 the blood. The blood is contained in a vast svstem of 

 pipes, spreading through the whole body, connected 

 with a force-pump, — the heart, — which, by its position 

 and by the contractions of its valves, keeps the blood 

 constantly circulating in one direction, never allowing it 

 to rest ; and then, by means of this circulation of the 

 blood, laden as it is with the products of digestion, the 

 skin, the flesh, the hair, and every other part of the 

 body, draws from it that which it wants, and every one 

 of these organs derives those materials which are 

 necessary to enable it to do its work. 



The action of each of these organs, the performance 

 of each of these various duties, involve in their operation 

 a continual absorption of the matters necessary for their 

 support, from the blood, and a constant formation of 

 waste products, which are returned to the blood, and 

 conveyed by it to the lungs and the kidneys, which are 

 organs that have allotted to them the office of extract- 

 ing, separating, and getting rid of these waste products ; 



