ORGANIZABLE PRINCIPLES. 413 



first, the rapidity of the pulse and the number of the respirations are increased, 

 and the animal appears to suffer little or no inconvenience for an hour ; but 

 symptoms of coma then gradually develop themselves, and death ensues in 

 six, ten, or twelve hours. If the animals are removed into the air before the 

 insensibility is considerable, they then quickly recover. When the body is 

 examined, the heart is seen beating strongly, while the diaphragm is motion- 

 less ; the whole blood in the veins, as well as in the arteries, is of a bright 

 scarlet colour ; and several of the membranous surfaces have the same tint. 

 The blood is observed to coagulate with remarkable rapidity ; and it is to the 

 alteration in its properties, occasioned by the hyper-arterialization, and indicated 

 by this condition, that we are probably to attribute the fatal result. There can 

 be no doubt that, in this instance, an undue amount of oxygen is absorbed. 

 Death is also caused by the inhalation of several gases of an irritant character, 

 such as sulphurous, nitrous and muriatic acids ; but it is doubtful how far they 

 are absorbed, or how far their injurious effects are due to the abnormal action 

 which they excite in the lining membrane of the air-cells and tubes. It cannot 

 be doubted, that miasmata and other morbific agents diffused through the at- 

 mosphere, are more readily introduced into the system through the pulmonary 

 surface than by any other ; and our aim should therefore be directed to the 

 discovery of some counteracting agents, which can be introduced in the same 

 manner. The pulmonary surface affords a channel for the introduction of cer- 

 tain medicines that can be raised in vapour when it is desired to affect the 

 system with them speedily and powerfully ; such are iodine, mercury, tobacco, 

 stramonium, &c. 



CHAPTER XI 



OF NUTRITION. 



551. THE Function of Nutrition essentially consists of the conversion of the 

 fluid alimentary materials, prepared by the digestive process, and introduced 

 into the system by absorption, into organized tissue, possessed of certain pro- 

 perties which inorganic matter never exhibits, and which, being neither phy- 

 sical nor chemical, are termed Vital. We shall hereafter see reason to believe 

 that the manifestation of these vital properties, which gives rise to the various 

 phenomena of life, is to be considered as the result of the process of organiza- 

 tion, to which matter is subjected in the living body ( 560). 



I. Organizable Principles. 



552. It has been shown ( 467) that the Chyle taken up by the lacteals is 

 composed of water holding albumen and saline matter in solution, and having 

 oily particles suspended in it. Albumen may be regarded as the proximate 

 element, at the expense of which, in conjunction with fatty matter (which 

 never itself undergoes organization as such, 16), all the tissues of the animal 

 body are ultimately formed. In this assumption we seem justified by two very 

 obvious considerations. First, in the egg of a bird, (or any other oviparous 



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