THE CONSERVATION OF ENERGY, 343 



THE CONSERVATION OF ENERGY IN THOSE OF 

 ADVANCING YEARS. 



By J. MADISON TAYLOR, A.M., M.D., 



PHILADELPHIA. 



nnHE study of the conditions and changes in the tissues of human 

 -^ beings as they pass beyond middle age would seem at first sight 

 to be of wide-spread interest. Upon the very simplest presentation 

 of the matter it will be universally admitted to be of the greatest im- 

 portance. The first principle of economics is not so much what we 

 win in any line of industry as what we save; this is the essence of the 

 conservation of values. What matters it how well the child is pro- 

 vided with opportunities for growth and how excellently the young 

 adult is developed in the fullness of such strength as is compatible 

 with individual opportunity; how high a degree of eflSciency, mental 

 or physical, can be attained, if all this is to last but for a few brief 

 years of practical utility? Again, allowing ourselves to indulge in a 

 more selfish view, what does it profit us if we shall acquire place and 

 power and the means by which we may be able to enjoy life, as we 

 have learned to live it through years of experience and the exercise 

 of careful choice, if we are to become speedily cut off from the con- 

 tinuance of the enjoyment of those privileges the product of matured 

 judgment and the full energizing of our powers? It is to me a re- 

 markable, indeed an astonishing, fact in searching for data on the 

 subject of senility which one would naturally assume to have grown 

 up in the enormous field of medical literature, that so little is to be 

 found bearing on this subject. There are here and there references 

 to old age and the phenomena of senility in a few of the standard 

 works on physiology, far fewer than the subject would seem to warrant. 

 The subject does not seem to have aroused much interest in the great 

 authorities on medicine, although there are some crisp and vigorous 

 articles which are valuable and interesting. 



My own studies have been most largely in the line of growth and 

 development of children and yet interest by no means ends there, 

 and my attention has been drawn to this matter through a constant 

 study based upon part medical research and part individual interest 

 in the whole question of bodily development and the possibilities which 

 lie in this direction for the advance of individual efficiency in all 

 periods of life. It has seemed that the phenomena of degeneration 

 are present in most disturbances referable to those of the nerves and 

 their centers where the analogue of senile changes constantly appears. 



