384 THE MODERN HORSE DOCTOR. 



(carbonic acid and water,) through the lungs and skin. Those 

 incombustible, azotic matters, separated from the blood in tho 

 form of urea, pass through the urinary channels. The oxygen 

 of the air is continually producing combustion and decompo- 

 sition of the living animal fibre. 



"VII. This action of combustion and decomposition is the 

 more potent the more the acts of respiration and circulation are 

 accelerated, and the contact of the air with the blood becomes, in 

 consequence, the oftener repeated. 



" Work cannot be performed without the acts of respiration and 

 the pulsations of the heart becoming more energetic, and pro- 

 portionably so with the speed and intensity of the work ; the 

 consequence of which is, to bring the organic fibre oftener into 

 the presence of oxygen, and so to hasten combustion and 

 decomposition. 



" Chemical analysis shows that the products of combustion, 

 exhaled through the skin and lungs, after a rapid course are con- 

 siderably augmented ; consequently, decomposition becomes aug- 

 mented under such circumstances. I pass over, in this estimate 

 of the causes of wear and tear in the animal machine, the nervous 

 exhaustion consequent on muscular contraction, because, although 

 I attach great importance to them, in this discussion they are not 

 necessary for my demonstration. 



" VIII. The orgasm is opposed to this oxidation, — 



" 1. By virtue of the innate force of cohesion existing between 

 its component particles — a force which for a certain time is able 

 to counteract the affinity resulting from the action of oxygen. 



" 2. And especially through the continually renewed influence 

 of the aliments introduced in sufficient quantity into the digestive 

 apparatus for furnishing the living tissue with the elements 

 proper for its reparation, and the oxygen of the air with com- 

 bustible matters fit for the development and completion of its 

 affinities, and through combination with it, for the production of 

 the required animal heat. 



" IX. But if, while we are exacting continually from the 

 animal machine a large demand of strength, — which, as I said 

 before, entails the introduction of a considerable quantity of at- 

 mospheric air into the air passages, — we do not afford a suf- 



