18 NERVES AND BRAIN DIAGRAM 1. 



Ottophaytt* (see Diagram 2), through which the food passes, and 

 with the larynx, where the air for respiration enters. The food 

 passes from the throat into the resophagus, and through that 

 into the stomach. There it changes its nature entirely, and 

 acquires an exceedingly disagreeable taste and odour. We 

 perceive this when we vomit; the stomach rejects its contents, 

 and we can already perceive how greatly the food has been 

 altered. It is still more altered when it passes into the intestines, 

 where it is mixed with the bile. Then it is absorbed by the surface 

 of the intestines, and is converted into blood ; and this in its turn 

 becomes flesh, muscles, tendons, bones, cartilages, skin, hair, nails, 

 humours in short, all the substances which compose the various 

 organs of the body. What is not thus absorbed and transformed 

 is expelled from the body. 



NERVES AND BRAIN. The Nerves are small white cords which 

 penetrate the whole body, and convey our wishes to every part. 

 If we wish to move the foot or hand, it is by means of the nerves 

 that our will contracts the muscles which move them. We 

 also feel by means of the nerves. If the nerves of the leg, for 

 instance, have been severed by a wound, the leg immediately 

 becomes insensible and incapable of movement, it is, as doctors 

 say, paralysed. 



The nerves sometimes cause great suffering, and produce what 

 is called neuralgia. 



All the nerves in the body return to the spinal cord and to the 

 brain, which is a continuation of it. The spinal cord and the 

 brain are composed of a very soft substance, fortunately protected 

 by the skull and the vertebra, for the least touch which it sustains 

 is always followed by the most serious consequences. Part of this 

 substance is grey, and the rest white ; the first forms the surface 

 of the brain, the second is in the centre. The whole surface 

 of the brain is covered with large folds, which are called convo- 

 lutions. 



The Brain is the organ by which we feel, think, remember, 

 or ecide upon any action, such as reaching out the arm, or 



