9Z DADD'S VETERINARY MEDICINE AND SURQERl. 



color By union witli the oxygen of the atmosphere, 'It hai 

 changed its color to one of scarlet. ISext, the union of oxygen 

 with the carbon of the blood liberates carbonic acid gas and vapor. 

 The blood is now fit for circulation and for the renovation of the 

 tissues. It appears, therefore, that as carbon exists in the venous 

 blood, the lungs must be the pulmonary furnaces. The air-cells 

 are flues or safety-valves, the membrane of the cells being per- 

 meable to oxygen, yet suffers not the blood to escape. Pulmonary 

 combustion, therefore, bears some analogy to the combustion of 

 carljon or charcoal in a stove ; for, in that case, the oxygen causes 

 the generation or evolution of carbonic acid gas. 



Beief Description of the Anatomy of the Lungs. 



The lungs, in common parlance, are known as the lights. They 

 Kccupy the thoracic cavity, or chest. They are divided into right 

 and left lobes, with a septum or partition between, which maktis 

 a double organ. This partition is a duplicature of the pleura, or 

 membrane which completely lines the chest. When the lungs 

 are healthy and properly inflated, they occupy the whole cavity of 

 the chest ; but when an action of expiration is effected, they are in 

 a comparative state of collapge. occupying but a very small portico 

 of the thoracic cavity. The lungs are composed of arteries, vein?, 

 absorbents, bronchial tubes, air-cells, and also what is known 'dn 

 their parenchyma, or substance. A healthy lung, when thrown 

 into water, will float on the surface ; while, on the other hand, a 

 diseased lung, in a state of hepatization or condensation, sinks like 

 a stone. In the fetal state, and when the lungs have never been 

 inflated, they also sink when thrown into water. 



Spasm of the Muscles of the Glottis and Epiglottis. 



The aperture leading into the larynx and wind])ipe is termed 

 the glottis. Spasm of the muscles of the glottis is one of the most 

 terrible accidents that can possibly occur in either man or horse 

 I view it in the light of an accident, because it usually occurs 

 without warning or any other premonitory symptoms, selecting its 

 victims in the very prime of life, and carrying them off, usually, 

 in the course of a very few seconds. The terms cramp and spasm 

 mean the same thing. When a man, while bathing in the river 



