94 THE CAUSATION OF DISEASE. 



when the habits and thoughts of early years are apt to re-assert 

 themselves in full sway. Since all habits are acquired struc- 

 tural peculiarities, it follows that the shaking off of a habit is 

 •the disappearance of such a structural peculiarity. 



Now these considerations have practical application for the 

 physician, because many habits are capable of affecting the 

 health for good or evil. It is needless to speak of the countless 

 healthy and unhealthy ones, such as the habit of regularly 

 going to stool, or the baneful habit of " drinking." 



Our proposition again holds true in respect of actual disease. 

 The longer a disease lasts, the less is the chance of recovery. 

 Hence the necessity, where possible, of nipping it in the bud. For 

 instance, an acute disease like pneumonia or acute nephritis has a 

 much better prognosis than one that is chronic — to wit, granular 

 kidney — from the very fact that the one is of recent origin 

 while the other has lasted some time. It might be argued, " Of 

 course, because the very fact of its chronicity suggests that it 

 was from the beginning destined to become chronic." This 

 is quite true, but, altogether apart from such a consideration, 

 a chronic disorder is less likely to get cured, for the longer 

 it lasts the faster does it cling, by making a deep impress upon 

 the body fabric; and even if we were able to check the progress 

 of a chronic disease — that is to say, remove those causes which 

 may have destined it to be chronic from the beginning — this 

 deep impress would still remain. Take as an example granular 

 kidney. The precious protoplasm, so cunningly adapted to the 

 removal of the nitrogenous sewage, is crushed and destroyed by 

 the growth of a dense fibrous tissue, which it were folly for us 

 to attempt to remove ; moreover, the heart, arteries, and many 

 other tissues are markedly affected, so that the disease can no 

 longer be flung off, leaving the body as it was before. But 

 "this may happen in acute pneumonia or nephritis, because the 

 structural changes of a few weeks' duration are, so to speak, of 

 a more superficial nature. 



II. What is true of the individual is true of the race. 

 " Those characters which are of most recent ancestral date show 

 the greatest tendency to disappear, or, more accurately, not to 

 appear, in the offspring." Natural variations of great ancestral 

 age — characters, that is to say, which have passed down many 



