Page:Popular Science Monthly Volume 64.djvu/414

410 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 tendency toward disease, and many of these can be recognized in their incipience 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 resistance, 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.

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, controllable. With that form of obesity which is not altogether manageable 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