1870.] BARKER — ON VITAL AxND PHYSICAL FORCES. 417 



nature ever flee from each other, and separates that which is 

 incessantly striving to unite. Recognize, therefore, in the Rhodian 

 Genius, in the expression of his youthful vigor, in the butterfly on 

 his shoulder, in the commanding glance of his eye, the symbol of 

 vital force as it animates every germ of organic creation. The 

 e:irthly elements at his feet are striving to gratify their own 

 desires and to mingle with one another. Imperiously the (JeniuS 

 threatens them with upraised and high-flaming torch, and compels 

 them, regardless of their ancient rights, to obey his laws. Look 

 now on the new work of art; turn from life to death. The but- 

 terfly has soared upward, the extinguished torch is reversed, and 

 the head of the youth is drooping ; the spirit has fled to other 

 spheres, and the vital force is extinct. Now the youths and 

 maidens joiu their hands in joyous accord. Earthly matter again 

 resumes its rights. Released from all bonds, they impetuously 

 follow their natural instincts, and the day of his death is to them a 

 day of nuptials.' 



The view here put by Humboldt into the mouth of Epicharmus 

 may be taken as a fair representation of the current opinion of all 

 ages concerning vital force. To-day, as truly as seventy-five years 

 ago when Huniboldt wrote, the mysterious and awful phenomena 

 of life are commonly attributed to some controlling agent residing 

 in the organism — to some independent presiding deity, holding it 

 in absolute subjection. Such a notion it was which prompted 

 Heraclitus to talk of a universal fire. Van Helmont to propose his 

 Archgeus, Ilofmann his vital fluid, Hunter his materia vitce diffusa, 

 and Humboldt his vital force.- All these names assume the exist- 

 ence of a material or immaterial something, more or less separable 

 from the material body, and more or less identical with the mind 

 or soul, which is the cause of the phenomena of living beings. But 

 as science moved irresistibly onward, and it became evident that 

 the forces of inorganic nature were neither deities nor imponder- 

 able fluids separable from matter, but were simple aff'ections of it, 

 analogy demanded a like concession in behalf of vital force.^ From 

 the notion that the effects of heat were due to an imponderable 

 fluid called caloric, discovery passed to the conviction that heat 

 was but a motion of material particles, and hence inseparable from 

 matter. To a like assumption concerning vitality it was now but 

 a step. The more advanced thinkers in science of to-day, there- 

 fore, look upon the life of the living form as inseparable from its 

 substance, and believe that the former is purely phenomenal, and 



