772 THE POPULAR SCIENCE MONTHLY. 



part." Stall we ascribe a " vital principle " to the unorganized crystal 

 as well as to the organized vegetable or animal tissue ? 



The mysteries of nature are not all confined to life-expressions. 

 Who shall explain the ultimate nature of crystallization, which, under 

 the laws of fixed axial ratios, gives to each variety such definite and 

 invariable form ? Who shall explain the flower's perfume ? Where 

 is the " vital force " in the seed which lies for ages in the tomb of 

 some Pharaoh ? Does " vital force," as an independent entity, which 

 works contrary to physical and chemical laws, thus imprison itself and 

 voluntarily submit to what must be, to it, a death ? If it acts independ- 

 ently of the physical forces of nature, why has it not furnished evi- 

 dence thereof in some way or at some time ? How is life made active 

 in this seed so long dried and practically dead ? Not by any occult 

 influence at discord with organic growth, but simply by environing the 

 seed with conditions favorable to physical well-being. Heat, light, 

 and moisture — all physical and chemical agents — soon revivify this 

 seed, and evidence is added to sustain the proposition that, while " the 

 present state of knowledge furnishes us with no link between the liv- 

 ing and the not-living," yet are both actuated by forces of the same 

 kind. " Vital force," therefore, is, in reality, only another term for 

 the properties of matter ; it denotes simply the causes of certain great 

 groups of natural operations, as we employ the terms "electricity" 

 and " electrical force " to denote others. But to use the term " vital- 

 ity " or " vital force " in the sense of an entity, which acts as an effi- 

 cient cause of vital phenomena, is an assumption as absurd as to assume 

 that " * electric,' ' attractive,' and * chemical ' forces are entities which 

 determine the phenomena of electricity, chemism, and gravitation." 



" If we knew all the laws of the composition of matter, and all the 

 changes of which it is capable, every phenomenon which any given 

 substance presents must be caused either by something taking place 

 in the substance or by something taking place out of it, but acting 

 upon it. Those mysterious forces, whether they be emanations from 

 matter or whether they be merely properties of matter, must, in an 

 ultimate analysis, depend either on the internal arrangement or on the 

 external locality of their physical antecedents. However convenient, 

 therefore, it maybe, in the present state of our knowledge, to speak'of 

 vital principles, imponderable fluids, and elastic ethers, such terms can 

 only be provisional, and are to be considered as mere names for that 

 residue of unexplained facts which it will be the business of future 

 ages to bring under generalizations wide enough to cover and include 

 the whole." 



As mechanical energy manifests different powers and results as it 

 operates through differently constructed mechanisms, so vital energy 

 becomes more complex in its manifestations as the organism through 

 which its work is displayed is more complicated in structure. 



Jevons has well defined the physiological significance of "vital 



