BY A. JEFFERIS TURNER, M.D. 35 



and unaccustomed motions, and then returns to rest again, to be 

 ever replaced with fresh particles as long as the air-vortex 

 continues its brief career. So during life dissolution is an 

 unceasing process, and the living organism is but a temporary 

 resting place of migratory atoms from the non-living world. 

 Furthermore, it is also certain that there is no creation or 

 destruction of force in the living organism. Here, as elsewhere, 

 the rule of the conservation of energy holds good. The greater 

 part of the vegetable world derives its energy direct from the 

 sun's rays, and stores it up in the form of chemical combina- 

 tions. The animal world, destitute of this power, appropriates 

 the energy stored up by plant life by devouring these complex 

 chemical substances, albumen, fat, starch, sugar, &c. Its energy 

 is derived from the chemical changes which result iu the 

 combination of the contained carbon, hydrogen, &c., with the 

 oxygen of the air. This energy is given off mostly in the form 

 of heat, a smaller fraction in the form of mechanical work, 

 which for the most part is also soon converted into heat. So 

 that all life derives its energy from the sun, and sooner or later 

 gives it back in the form of heat. In the process there is 

 change, transmutation of force, but neither loss nor gain ; one 

 form of vibration is replaced by another, but the chain is never 

 broken. As a late distinguished physicist wrote, in lines which, 

 though half jocular in form, contain serious thought : — 



" When earth and sun are frozen clods, 



" And, all its energy degraded, 



" Matter to Ether shall have faced, 



" We, that is all the work we've done, 



" As waves in ether shall for even run 



" In swift expanding spheres through heavens beyond the sun." 



Having grasped this conception of the living organism as a 

 temporary halting place of atoms derived from the inorganic 

 world as a temporary focus of energy derived from without and 

 passing without again, must we add to matter and force a 

 hypothetical something called " vitality ? " Admitting to the 

 full the vast difference between the phenomena of living and 

 non-living matter, and the impossibility of picturing to oneself 

 any mechanical arrangement of atoms and molecules, which 

 will explain the former, I ask do we make the problem any 

 clearer by such an assumption ? Indeed has the word vitality 

 any meaning that we can figure before our minds. Is it any 

 more than a verbal expression, a word that merely covers 



