Human Physiology. 



IV. includes Developmental Diseases, i. In children, as mal- 

 formations, idiocy, teething; 2. Of women, relating to men- 

 struation and childbirth; 3. Of old age; 4. Of nutrition, 

 as atrophy, debility, &c. 



It is evident, in looking over this formidable classification of 

 the infirmities and diseases of humanity, that nearly the whole 

 of them are clearly, readily, and easily preventable ; that they 

 are inherited, caught, or produced by avoidable conditions, as 

 we shall see more fully when treating of the causes of disease. 

 The miasmatic diseases, which are caused by some taint, germ, 

 or poison in the atmosphere, acting upon an impure blood and 

 weakened nervous power, have all a similar character. What 

 we call the disease the fever, the pain, the hurried circulation, 

 the hot skin, the eruptive action is a process set up by nature 

 to expel the morbid matter from the system. When that mat- 

 ter comes to the surface, and is cast out, or when the body is 

 purified by the skin, lungs, the action of the bowels, in whatever 

 way, the disease is cured. When that action fails, and the 

 poison falls upon the brain, or paralyses the action of the 

 nerves of organic life, the result is death. 



The same effort is set up, and the same struggle takes place 

 in the enthetic or implanted diseases. Syphilis, it is almost 

 universally admitted, is the reaction of the system against a 

 specific poison of unknown origin. No one has ever seen it 

 arise spontaneously as far as we know, it is always communi- 

 cated by one person to another inherited, tainting the germ 

 of life, or taken by absorption into the circulation. After a 

 certain period of what has been called incubation, a diseased 

 action really an effort to expel the poison is set up. If only 

 partially successful a second effort is made at a later period 

 over a larger surface in eruptions on the skin; later still there 

 may be suppurations and abscesses; but in weakened consti- 

 tutions all these efforts may fail; and the poison, in modified 

 forms, may exj though several generations Some animal 



