4IO POPULAR SCIENCE MONTHLY. 



made upon the conditions governing senile processes, induces a tendency 

 to start from wrong premises. It is important that these researches 

 should be strongly modified by a comparison between normal and 

 physiologic changes, otherwise right conclusions are obscured. This 

 practical point must never be lost sight of by observers and clinicians 

 in the study of the individual and his ailments. In the study of the 

 processes of the individual the ailments are too frequently the only 

 conditions considered and the normal changes overlooked. 



Clinicians recognize what they call diatheses. A diathesis is a tend- 

 ency toward disease, and many of these can be recognized in their in- 

 cipience and differentiated in such manner that preventive measures can 

 be employed and earlier changes limited and improved. Disease is 

 the domain of pathology, the study of abnormal conditions induced by 

 changes outside the realm of individual processes. The diathesis gives 

 evidence of a lessened coefficient of resistance, a lowering in noble 

 activities and exhaustion of the powers of repair. This is probably 

 because the power of attraction is not the same in each person and is of 

 variable intensity. Protoplasm has not the same proportions in its 

 composition, hence variations arise in the phases of its evolution. 

 Assuming then the variability in chemic structure, and hence a variable 

 power of attraction in protoplasm, hence, also in the coefficient of re- 

 sistance, these thoughts will aid in explaining congenital and queer 

 constitutional peculiarities, and often inexplicable differences in races, 

 families and individuals. It is a matter of common observation that 

 in some families senile changes occur much more early than in others, 

 and yet there may be little of degenerative change apparent or probable 

 because of the vigor of the individual. As the gradual steps of growth 

 lead to development, so does the phase of existence called senescence 

 merge insidiously toward the ending called death, through a progressive 

 and insensible diminution in all the organic activities. Death should 

 be regarded as a normal function. Ordinarily it is free from pain 

 and hence should be free from sadness. 



Obesity. 



Excessive fatness, or polysarcia, is not confined to advancing years, 

 it is observed at all ages; but the quality of the accumulation in early 

 years differs from that seen in late middle life. During the 

 earlier years excessive gain in weight is usually the product of full 

 digestive capacity with a somewhat lessened eliminative power and can 

 be met by reduction in diet and active exercises, and is, as a rule, con- 

 trollable. With that form of obesity which is not altogether man- 

 ageable in young people or those on the hither side of middle life we 

 have nothing to do, except in so far as we should discuss this condition 

 and its progress when encountered in later years. Again in women 



