168 THE POPULAR SCIENCE MONTHLY. 



from physical to chemical, or from chemical to vital, is not, as far as 

 we can see, by sliding scale, but suddenly. The groups of phenomena 

 which we call physical, chemical, vital, animal, rational, and moral, do 

 not merge into each other by insensible gradations. In the ascension 

 scale in the evolution of the higher forces there are places of rapid 

 paroxysmal change. 



b. Vital force is transformed into physical and chemical forces ; but 

 it is not on that account identical with physical and chemical force, and 

 therefore we ought not, as some would have us, discard the term vital 

 force. There are two opposite errors on this subject : one is the old 

 error of regarding vital force as something innate, underived, having 

 no relation to the other forces of Nature ; the other is the new error 

 of regarding the forces of the living body as nothing but ordinary 

 physical and chemical forces, and therefore insisting that the use of the 

 term vital force is absurd and injurious to science. The old error is 

 still prevalent in the popular mind, and still haunts the minds of many 

 physiologists ; the new error is apparently a revelation from the other, 

 and is therefore common among the most advanced scientific minds. 

 There are many of the best scientists who ridicule the use of the term 

 vital force, or vitality, as a remnant of superstition ; and yet the same 

 men use the words gravity, magnetic force, chemical force, physical 

 force, etc. Vital force is not underived — is not unrelated to other 

 forces — is, in fact, correlated with them ; but it is nevertheless a dis- 

 tinct form of force, far more distinct than any other form, unless it be 

 still higher forms, and therefore better entitled to a distinct name 

 than any lower form. Each form of force gives rise to a peculiar 

 group of phenomena, and the study of these to a peculiar department 

 of science. Now, the group of phenomena called vital is more pecul- 

 iar, and different from other groups, than these are from each other ; 

 and the science of physiology is a more distinct department than either 

 physics or chemistry ; and therefore the form of force which deter- 

 mines these phenomena is more distinct, and better entitled to a dis- 

 tinct name, than either physical or chemical forces. De Candolle, in 

 a recent paper, 1 suggests the term vital movement instead of vital 

 force ; but can we conceive of movement without force ? And, if the 

 movement is peculiar, so also is the form of force. 



c. Vital is transformed physical and chemical forces ; true, but the 

 necessary and very peculiar condition of this transformation is the 

 previous existence then and there of living matter. There is some- 

 thing so wonderful in this peculiarity of vital force that I must dwell 

 on it a little. 



Elements brought in contact with each other under certain physi- 

 cal conditions — perhaps heat or electricity — unite and rise into the 

 second plane, i. e., of chemical compounds ; so also several elements, 

 C, H, O and 1ST, etc., brought in contact with each other under certain 

 1 Archives des Sciences, vol. xlv., p. 345, December, 1872 



