8. Circulation — Heart, Arteries, Capillaries, and Veins — 

 Diseases, &c. 



g. Respiration — Lungs — Bronchial Tubes — Diseases. 



10. Nerves — Brain, Eye, and Ear — Diseases. 



11. Skin — Hair Follicles, Sweat Glands, &c. — Affections — Diseases. 



12. Urinary and Generative Organs — Parturition and Diseases. 



II. When all these various structures are in a normal condition, the 

 body may be said to be in a state of health, to maintain which, 

 certain materials, commonly called food, are necessary so as to replace 

 the changes of matter (more or less accelerated) that is ever going 

 on, as there is not a thought or a movement of the body without 

 some expenditure of tissue. This tissue must be renewed, and this 

 is done by the process of Nutrition, which process belongs to all 

 organised structures. Nutrition is upheld and carried on by means 

 of the food eaten, which, when digested, passes into the blood, and 

 is carried by it to the various parts of the body. (Sec Digestive 

 Oygans A.) In the animal kingdom, before healthy nutrition can be 

 successfully maintained, certain conditions are required, viz. : 



(i) The part to be nourished must be in proper state of health. 



(2) The blood must be pure, and not too far distant. (There are 



some structures into which the blood does not go, it only flows 

 7ieay ; for instance, the cartilage covering the ends of bones 

 in the formation of joints. In such cases nutrition is carried 

 on by "imbibition," or sucking up.) 



(3) The temperature or heat of the part must be normal. (If the part 



shows a temperature higher than the normal and natural, 

 then healthy assimilation is interfered with. On the other 

 hand, everyone has read of a man's toes being frozen off, in 

 the arctic regions, through extreme cold, thus showing the 

 necessity of normal heat.) 



(4) All parts must be under the control or influence of the nervous 



system. 



