THE GENERAL CONSTITUTION OF LIVING BEINGS. 81 



posed upon minds that took every thing to be real except 

 the reality itself. 



Some biologists of the same school have been led by 

 a similar mistake to the notion of a supposed property 

 inherent in living tissues, the peculiarity of which is the 

 power they have of setting up action under the most vary- 

 ing influences. They have given this property the name 

 of irritability, the same peculiarity formerly regarded by 

 Broussais as a specific one, and used by him as the main- 

 stay of his theory. This irritability, neither specific nor 

 spontaneous, is nothing else than the manifestation of one 

 of the five fundamental properties of organized substance. 

 At least it is always reducible to that, as Robin has 

 shown, and could not from any point of view be regarded 

 as a new property. The anatomical elements are in a state 

 of incessant transformation, and therefore the least thing 

 may disturb their equilibrium, and bring about what is 

 called irritation. Let a single atom of their mass experi- 

 ence a derangement of any kind, the remainder of them 

 undergoes its reaction, and all the properties of the element 

 are differently affected. Heat, cold, electricity, chemical 

 substances, in a word, any causes that can affect the mo- 

 lecular condition of the elements, thus act on organized 

 substance. It is the instability in a system of such restless 

 and fleeting changes which makes it so quick to feel all in- 

 fluences, so irritable ; but, we repeat, irritants call forth in 

 it nothing more than the exhibition of the properties we 

 have mentioned. 



" Cleave an atom," the Persian poet says, " and you will 

 find in it a sun." So the anatomical element, examined in 

 its deepest recesses, yields us the magnificent vision of life. 

 It unveils for us its secret machinery, its hidden energies, 

 its latent springs, its concealed forces ; teachings full of 

 light, which have transformed the conceptions of philoso- 

 phy regarding the world of life. 



