90 OADD’S VETERINARY MEDICINE AND SURGERY 
color By union with the oxygen of the atmosphere, ‘t has 
changed its color to one of scarlet. Next, 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 
carbon or charcoal in a stove; for, in that case, the oxygen causca 
the generation or evolution of carbonic acid gas. 
Brier DESCRIPTION OF THE ANATOMY OF THE Lunas. 
The lungs, in common parlance, are known as the lights. They 
vccupy the thoracic cavity, or chest. They are divided into right 
and left lobes, with a septum or partition between, which makes 
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 iu 
a comparative state of collapge, occupying but a very small portion 
of the thoracic cavity. The lungs are composed of arteries, veins, 
absorbents, bronchial tubes, air-cells, and also what is known as 
their parenchyma, or substance. A healthy lung, when thrown 
into water, will float ov the surface; while, on the other hand, a 
diseased lung, in a state of hepatization or condensation, sinks like 
astone. 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 windpipe is termed 
the glottis. Spasm of the muscles of the glottis is one or 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 occury 
without warning or any uther 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 
meau the same thing. When a man, while bathing in the river 
