no POPULAR SCIENCE MONTHLY. 



until tliis time lias evidently been becoming clearer and stronger? 

 Again, people who are constitutionally tending to mental breakdown 

 are very apt to load themselves down with duties and get themselves 

 into situations which must necessarily prove to be too onerous and too 

 perplexing for their poorly developed strength and' skill. Of course, 

 circumstances often require this. Many times, however, there is a 

 kind of impulsive restlessness coupled with a short-sighted optimism, 

 both constitutional, which, altogether more than ordinary circum- 

 stances, are to blame for undue assumption of work or care, and whose 

 effect is, perhaps, best seen in the persistent tendency of such people 

 to originate and perpetuate exhausting habits, both of mind and body. 

 Thus, the habit of self-poisoning from poorly digested and poorly 

 assimilated food is easily acquired by such people, and always becomes 

 a source of progressive brain starvation and often of consequent men- 

 tal breakdown. Says Dr. A. S. Thayer (Journal of Medicine and 

 Science, vol. iii, page 173), " There is ground for belief that ex- 

 haustion — fatigue — is dependent upon poisoning of the cells of the 

 brain, muscles, and other tissues by the waste products of functional 

 activity." * Again, as already noted, perversions of the natural in- 

 stincts — of appetite for food, of desire for gain, of social or other 

 ambitions, and especially of the sexual impulse and its habitual in- 

 dulgence — fasten themselves upon such individuals with a perma- 

 nence and destructiveness that must almost of necessity lead to dis- 

 aster, f And so we may see that as a most natural, although often a 

 far-removed, result of unphysiological marriages, proceeding through 

 generations which have been thus predestinated to weakening 

 choices and practices, insanity finally appears to mark the ultimate 

 extent both of the mental disorganization and bodily inefficiency, 

 which extent is owing not only to the original initiating steps, but 

 also to subsequent stages of causation, progressively developed from 

 generation to generation. 



Another great source of vitiation of fhe stream of tendency is 

 found in two people who marry in a truly enough physiological 

 sense, but who find or force themselves in lives of wear and tear which 

 progressively unfit them for childbearing and child nurture. Poorly 

 calculated ambitions, unexpected difficulties to be surmounted, de- 

 pressing oppositions, with perhaps more or less actual disease or acci- 

 dent, largely account for this in a general way. Obviously, during 

 the child-rearing age, the effect of what parents arc obliged to en- 

 dure and execute upon the fortunes of progeny becomes a matter of 

 far-reaching importance. That anything which persistently exhausts 

 or overstrains the parents must tell in the later dynamic tendency and 



* See also Dr. Edward Cowles. Shattnek Lecture on Neiirasthenia. 



f See Peterson. The Stigmata of Degeneration. State Hospitals Bulletin, vol. i, p. 327. 



