ORGASM AND IRRITABILITY 221 



that in animals on the contrary it is very conspicuous ; for it produces 

 in them that remarkable property called irritabihty by which they are 

 distinguished. 



Let us first study it in animals. 



Of Animal Orgasm. 



By animal orgasm, I mean that curious condition of the supple 

 parts of a living animal, in which there exists at every point a pecuHar 

 tension, of such strength that the parts are able immediately to react 

 to any impression that they may experience, and do in fact react on 

 the moving fluids which they contain. 



This tension, the degree of which varies in the different parts, con- 

 stitutes what physiologists call the tone of the parts ; it seems to be 

 due as I have already said to the presence of an expansive fluid which 

 penetrates these parts, remains in them for a certain period and keeps 

 their molecules separated to some distance from one another though 

 without destroying their coherence ; some of the fluid suddenly escapes 

 on any contact, leading to a contraction, but it is promptly restored 

 again. 



Thus at the moment of the dissipation of the expansive fluid dis- 

 tending any part, this part subsides on itself as a result ; but it is 

 promptly restored to its previous distention by the arrival of new 

 expansive fluid. Hence it follows that the orgasm of this part gives 

 it the property of reacting on the visible fluids which affect it. 



This tension in the soft parts of hving animals does not go so far 

 as to break up the cohesion of their molecules, or to destroy their 

 adhesiveness, agglutination and firmness, so long as the intensity of 

 orgasm does not exceed a certain point. But the tension prevents 

 the faUing together and collapse of the molecules which would occur 

 if this tension did not exist ; for the soft parts do actually subside in a 

 remarkable way as soon as the tension is removed. j 



Indeed among animals, and even among plants, the extinction of 

 orgasm, which only occurs on the death of an individual, gives rise 

 to a relaxation and subsidence of the supple parts, making them 

 softer and more limp than in the living state. This has given rise to 

 the belief that these limp parts found in old people after death have 

 escaped the rigidity which gradually comes over the organs during 

 life. 



The blood, and especially the arterial blood, of animals whose 

 organisation is highly complex, itself possesses a sort of orgasm ; 

 for it is during fife suffused with various gases which develop within 

 it and become modified there. Now these gases may also contribute 

 to the stimulation of the organic acts of irritability, and consequently 



