THE VITAL FORCE. 



" Yim internam, quse chymicse affinitatis vincula resolvit, 

 atque obstat, quominus elementa corporum libere conjun- 

 gantur, vitalem vocamus. Itaque nullum certius mortis 

 criterium putredine datur, qua primse partes vel stamina 

 rerum, antiquis juribus revocatis, affinitatum 1-egibus parent. 

 Corporum inanimorum nulla putredo esse potest." (Yide 

 Apliorismi ex doctrina Physiologise chemica3 Plantarum, in 

 Humboldt, Mora Fribergensis subterranea, 1793, p. 133- 

 136). 



I have placed in the mouth of Epicharmus the above 

 propositions, which were disapproved by the acute Yicq 

 d'Azyr, in hisTraite d'Anatomieet de Physiologic, T. i.p. 5, 

 but are now entertained by many distinguished persons 

 among my friends. Reflection and continued study in the 

 domains of physiology and chemistry have deeply shaken my 

 earlier belief in a peculiar so-called vital force. In 1797, 

 at the close of my work entitled "Yersuche iiber die 

 gereizte Muskel und Nervenfaser, nebst Yermuthungen 

 iiber den chemischen Process des Lebens in der Thier und 

 Pflanzenwelt" (Bd. ii. S. 430-436), I already declared that 

 I by no means regarded the existence of such peculiar vital 

 forces as demonstrated. Since that time I have no longer 

 called peculiar forces what may possibly only be the opera- 

 tion of the concurrent action of the several long-known 

 substances and their material forces. We may, however 

 deduce from the chemical relations of the elements a safer 

 definition of animate and inanimate substances, than the 

 criteria which are taken from voluntary motion, from the 

 circulation of fluids within solids, from internal appropria- 



